source large_string | license large_string | redistributable bool | game_id large_string | pgn large_string | fen large_string | move_uci large_string | move_san large_string | comment large_string | white_elo null | black_elo null | task large_string | level large_string | detail large_string | verdict large_string | eval_after dict | eval_before dict | facts list | user_message large_string | chat_prompt large_string |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
mate | MIT | true | mate_00a56c3d2aabc5bf | r5k1/ppp3pp/8/4P3/6b1/3BP1P1/PP1R2p1/2K2rR1 w - - 3 22 | d3f1 | Bxf1 | Replace the smaller piece with a higher-value one, gaining a strategic edge. Tactical line: Bxf1 gxf1=R+ Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Only move | {
"fen": "r5k1/ppp3pp/8/4P3/6b1/4P1P1/PP1R2p1/2K2BR1 b - - 0 22",
"pvs": [
{
"score": {
"type": "cp",
"value": 270
},
"moves": [
"g2f1q",
"g1f1",
"a8e8",
"d2d5",
"b7b6",
"a2a4",
"g4e6",
"d5d4",
"e6h3",
... | {
"fen": "r5k1/ppp3pp/8/4P3/6b1/3BP1P1/PP1R2p1/2K2rR1 w - - 3 22",
"pvs": [
{
"score": {
"type": "cp",
"value": 270
},
"moves": [
"d3f1",
"g2f1q",
"g1f1",
"a8e8",
"d2d5",
"b7b6",
"a2a4",
"g4e6",
"d5d4",
... | [
"Bxf1 attacks the pawn on g2 together with the rook on g1.",
"After Bxf1, Black's best reply is gxf1=Q+.",
"Black has a check: gxf1=R+.",
"Black can capture the bishop on f1 with gxf1=N.",
"White threatens Bc4+.",
"Black is up a pawn.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: r5k1/ppp3pp/8/4P3/6b1/3BP1P1/PP1R2p1/2K2rR1 w - - 3 22
White to move, move 22.
Move played: Bxf1.
Verdict: Only move.
White's winning chances: 73% → 73%.
Best move: Bxf1.
Best line: Bxf1 gxf1=Q+ Rxf1 Re8 Rd5 b6.
Facts:
- Bxf1 attacks the pawn on g2 together with th... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: r5k1/ppp3pp/8/4P3/6b1/3BP1P1/PP1R2p1/2K2rR1 w - - 3 22
White to move, move 22.
Move played: Bxf1.
Verdict: Only ... | |
mate | MIT | true | mate_00ee4204be658e23 | 2rq1rk1/1b6/p4p1p/1pb1B1p1/4n3/3B1N2/PPQ2PPP/R4RK1 w - - 2 19 | e5c7 | Bc7 | Plant the piece in a dominant spot, expanding its control over the board. Tactical line: Bc7 Qxd3 Qxd3 Rxc7 Nd2 Nxf2 | null | null | explain_move | beginner | short | Blunder | {
"fen": "2rq1rk1/1bB5/p4p1p/1pb3p1/4n3/3B1N2/PPQ2PPP/R4RK1 b - - 3 19",
"pvs": [
{
"score": {
"type": "cp",
"value": -452
},
"moves": [
"c5f2",
"c2f2",
"e4f2",
"c7d8",
"f2d3",
"d8e7",
"f8f7",
"a1d1",
"d3b2... | {
"fen": "2rq1rk1/1b6/p4p1p/1pb1B1p1/4n3/3B1N2/PPQ2PPP/R4RK1 w - - 2 19",
"pvs": [
{
"score": {
"type": "cp",
"value": 585
},
"moves": [
"d3e4",
"c5f2",
"c2f2",
"b7e4",
"a1d1",
"d8a5",
"e5c3",
"b5b4",
"c3d4... | [
"Bc7 attacks the queen on d8.",
"After Bc7, Black's best reply is Bxf2+.",
"After Bc7, Black captures the pawn on f2 with Bxf2+.",
"The bishop on c7 is not defended.",
"Black has a check: Bxf2+.",
"Black can capture the bishop on c7 with Rxc7.",
"White threatens Bxd8.",
"Material: equal.",
"Phase: m... | task: explain_move
level: beginner
detail: short
FEN: 2rq1rk1/1b6/p4p1p/1pb1B1p1/4n3/3B1N2/PPQ2PPP/R4RK1 w - - 2 19
White to move, move 19.
Move played: Bc7.
Verdict: Blunder.
White's winning chances: 90% → 16%.
Best move: Bxe4.
Best line: Bxe4 Bxf2+ Qxf2 Bxe4 Rad1 Qa5.
Facts:
- Bc7 attacks the queen on d8.
- After Bc... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 2rq1rk1/1b6/p4p1p/1pb1B1p1/4n3/3B1N2/PPQ2PPP/R4RK1 w - - 2 19
White to move, move 19.
Move played: Bc7.
Verdict:... | |
mate | MIT | true | mate_0138da63650825d7 | 6k1/R4Rp1/7p/2P4K/3bnPP1/P4n2/8/8 b - - 0 36 | e4g3 | Ng3+ | Switch the piece to a more advantageous place, increasing its mastery over the board. Tactical line: Ng3+ Kg6 Nh4# Checkmate! | null | null | explain_move | beginner | short | Only move | {
"fen": "6k1/R4Rp1/7p/2P4K/3b1PP1/P4nn1/8/8 w - - 1 37",
"pvs": [
{
"score": {
"type": "mate",
"value": -2
},
"moves": [
"h5g6",
"f3h4"
]
}
]
} | {
"fen": "6k1/R4Rp1/7p/2P4K/3bnPP1/P4n2/8/8 b - - 0 36",
"pvs": [
{
"score": {
"type": "mate",
"value": -2
},
"moves": [
"e4g3",
"h5g6",
"f3h4"
]
},
{
"score": {
"type": "cp",
"value": 236
},
"moves": [
... | [
"After Ng3+, White's best reply is Kg6.",
"White king is in check on h5.",
"White is up a minor piece in material.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 6k1/R4Rp1/7p/2P4K/3bnPP1/P4n2/8/8 b - - 0 36
Black to move, move 36.
Move played: Ng3+.
Verdict: Only move.
Black's winning chances: 100% → 100%.
Best move: Ng3+.
Best line: Ng3+ Kg6 Nh4#.
Facts:
- After Ng3+, White's best reply is Kg6.
- White king is in check on ... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 6k1/R4Rp1/7p/2P4K/3bnPP1/P4n2/8/8 b - - 0 36
Black to move, move 36.
Move played: Ng3+.
Verdict: Only move.
Blac... | |
mate | MIT | true | mate_0165dbb4217ef4f1 | 8/2pK3P/p5k1/2pP4/2P5/2b5/P7/8 w - - 0 47 | d7c7 | Kxc7 | Switch a lower value piece with a higher value piece, to gain an advantage. Tactical line: Kxc7 Kxh7 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Best | {
"fen": "8/2K4P/p5k1/2pP4/2P5/2b5/P7/8 b - - 0 47",
"pvs": [
{
"score": {
"type": "cp",
"value": 157
},
"moves": [
"g6h7",
"c7b6",
"a6a5",
"d5d6",
"h7g6",
"d6d7",
"c3f6",
"b6c5",
"g6f7"
]
}
]
} | {
"fen": "8/2pK3P/p5k1/2pP4/2P5/2b5/P7/8 w - - 0 47",
"pvs": [
{
"score": {
"type": "cp",
"value": 157
},
"moves": [
"d7c7",
"g6h7",
"c7b6",
"a6a5",
"d5d6",
"h7g6",
"d6d7",
"c3f6",
"b6c5",
"g6f7"
... | [
"After Kxc7, Black's best reply is Kxh7.",
"After Kxc7, Black captures the pawn on h7 with Kxh7.",
"Black has a check: Ba5+.",
"Black is up two pawns in material.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 8/2pK3P/p5k1/2pP4/2P5/2b5/P7/8 w - - 0 47
White to move, move 47.
Move played: Kxc7.
Verdict: Best.
White's winning chances: 64% → 64%.
Best move: Kxc7.
Best line: Kxc7 Kxh7 Kb6 a5 d6 Kg6.
Facts:
- After Kxc7, Black's best reply is Kxh7.
- After Kxc7, Black capture... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 8/2pK3P/p5k1/2pP4/2P5/2b5/P7/8 w - - 0 47
White to move, move 47.
Move played: Kxc7.
Verdict: Best.
White's winn... | |
mate | MIT | true | mate_01c88815cae0aa46 | r2q1rk1/1p2ppbp/p5p1/8/3NP1nP/8/PPPQ2P1/2KR2BR b - - 1 15 | g7h6 | Bh6 | Reassign the piece to a central area, where it exercises more control over the board. Tactical line: Bh6 Nf3 Bxd2+ Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Only move | {
"fen": "r2q1rk1/1p2pp1p/p5pb/8/3NP1nP/8/PPPQ2P1/2KR2BR w - - 2 16",
"pvs": [
{
"score": {
"type": "cp",
"value": -751
},
"moves": [
"d2h6",
"g4h6",
"c1b1",
"d8c8"
]
}
]
} | {
"fen": "r2q1rk1/1p2ppbp/p5p1/8/3NP1nP/8/PPPQ2P1/2KR2BR b - - 1 15",
"pvs": [
{
"score": {
"type": "cp",
"value": -751
},
"moves": [
"g7h6",
"d2h6",
"g4h6",
"c1b1",
"d8c8"
]
},
{
"score": {
"type": "cp",
... | [
"Bh6 attacks the queen on d2.",
"After Bh6, White's best reply is Qxh6.",
"White can capture the bishop on h6 with Qxh6.",
"Black threatens Bxd2+.",
"Material: equal.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: r2q1rk1/1p2ppbp/p5p1/8/3NP1nP/8/PPPQ2P1/2KR2BR b - - 1 15
Black to move, move 15.
Move played: Bh6.
Verdict: Only move.
Black's winning chances: 94% → 94%.
Best move: Bh6.
Best line: Bh6 Qxh6 Nxh6 Kb1 Qc8.
Facts:
- Bh6 attacks the queen on d2.
- After Bh6, White's ... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: r2q1rk1/1p2ppbp/p5p1/8/3NP1nP/8/PPPQ2P1/2KR2BR b - - 1 15
Black to move, move 15.
Move played: Bh6.
Verdict: Onl... | |
mate | MIT | true | mate_01d84a949a8425b9 | r4rk1/ppqn1ppp/3bp3/3pn3/3P1PQ1/2P3N1/PP4PP/R1B2RK1 w - - 0 14 | f4e5 | fxe5 | Swap a lower-value piece for a higher-value one to gain the advantage. Tactical line: fxe5 Nxe5 dxe5 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Only move | {
"fen": "r4rk1/ppqn1ppp/3bp3/3pP3/3P2Q1/2P3N1/PP4PP/R1B2RK1 b - - 0 14",
"pvs": [
{
"score": {
"type": "cp",
"value": 364
},
"moves": [
"d7e5",
"d4e5",
"d6e5",
"g1h1",
"b7b5",
"g3e2",
"a7a5",
"g4f3",
"c7c4... | {
"fen": "r4rk1/ppqn1ppp/3bp3/3pn3/3P1PQ1/2P3N1/PP4PP/R1B2RK1 w - - 0 14",
"pvs": [
{
"score": {
"type": "cp",
"value": 364
},
"moves": [
"f4e5",
"d7e5",
"d4e5",
"d6e5",
"g1h1",
"b7b5",
"g3e2",
"a7a5",
"g4f... | [
"fxe5 attacks the bishop on d6.",
"After fxe5, Black's best reply is Nxe5.",
"White threatens exd6.",
"Black is up a knight.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: r4rk1/ppqn1ppp/3bp3/3pn3/3P1PQ1/2P3N1/PP4PP/R1B2RK1 w - - 0 14
White to move, move 14.
Move played: fxe5.
Verdict: Only move.
White's winning chances: 79% → 79%.
Best move: fxe5.
Best line: fxe5 Nxe5 dxe5 Bxe5 Kh1 b5.
Facts:
- fxe5 attacks the bishop on d6.
- After... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: r4rk1/ppqn1ppp/3bp3/3pn3/3P1PQ1/2P3N1/PP4PP/R1B2RK1 w - - 0 14
White to move, move 14.
Move played: fxe5.
Verdic... | |
mate | MIT | true | mate_022f942a453fd749 | 3q1rk1/pb2nppp/4p2P/2p3P1/1r1P4/3B1Q2/PP3P2/2KR2NR w - - 0 22 | d3h7 | Bxh7+ | Sacrifice a piece to carve open a file or diagonal close to the enemy king Tactical line: Bxh7+ Kxh7 Trade the lower value piece for a higher value piece. | null | null | explain_move | club | short | Only move | {
"fen": "3q1rk1/pb2nppB/4p2P/2p3P1/1r1P4/5Q2/PP3P2/2KR2NR b - - 0 22",
"pvs": [
{
"score": {
"type": "mate",
"value": 4
},
"moves": [
"g8h7",
"h6g7",
"h7g7",
"f3f6",
"g7g8",
"h1h8"
]
}
]
} | {
"fen": "3q1rk1/pb2nppp/4p2P/2p3P1/1r1P4/3B1Q2/PP3P2/2KR2NR w - - 0 22",
"pvs": [
{
"score": {
"type": "mate",
"value": 4
},
"moves": [
"d3h7",
"g8h7",
"h6g7",
"h7g7",
"f3f6",
"g7g8",
"h1h8"
]
},
{
"sc... | [
"After Bxh7+, Black's best reply is Kxh7.",
"After Bxh7+, Black captures the bishop on h7 with Kxh7.",
"The bishop on h7 is not defended.",
"Black can capture the bishop on h7 with Kxh7.",
"Black king is in check on g8.",
"Material: equal.",
"Phase: middlegame."
] | task: explain_move
level: club
detail: short
FEN: 3q1rk1/pb2nppp/4p2P/2p3P1/1r1P4/3B1Q2/PP3P2/2KR2NR w - - 0 22
White to move, move 22.
Move played: Bxh7+.
Verdict: Only move.
White's winning chances: 100% → 100%.
Best move: Bxh7+.
Best line: Bxh7+ Kxh7 hxg7+ Kxg7 Qf6+ Kg8.
Facts:
- After Bxh7+, Black's best reply is ... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: club
detail: short
FEN: 3q1rk1/pb2nppp/4p2P/2p3P1/1r1P4/3B1Q2/PP3P2/2KR2NR w - - 0 22
White to move, move 22.
Move played: Bxh7+.
Verdict: O... | |
mate | MIT | true | mate_02377ba04d590070 | 2r5/5pp1/3kp2p/b2p4/P2K1P2/1B1R3P/1PP3P1/8 b - - 2 32 | a5b6 | Bb6# | Move the piece to an aggressive spot, enhancing its control over the board. Tactical line: Bb6# Checkmate! | null | null | explain_move | beginner | short | Only move | {
"fen": "2r5/5pp1/1b1kp2p/3p4/P2K1P2/1B1R3P/1PP3P1/8 w - - 3 33",
"pvs": [
{
"score": {
"type": "mate",
"value": -1
},
"moves": []
}
]
} | {
"fen": "2r5/5pp1/3kp2p/b2p4/P2K1P2/1B1R3P/1PP3P1/8 b - - 2 32",
"pvs": [
{
"score": {
"type": "mate",
"value": -1
},
"moves": [
"a5b6"
]
},
{
"score": {
"type": "cp",
"value": -7
},
"moves": [
"c8b8",
"d4... | [
"White king is in check on d4.",
"White is up a pawn.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 2r5/5pp1/3kp2p/b2p4/P2K1P2/1B1R3P/1PP3P1/8 b - - 2 32
Black to move, move 32.
Move played: Bb6#.
Verdict: Only move.
Black's winning chances: 100% → 100%.
Best move: Bb6#.
Best line: Bb6#.
Facts:
- White king is in check on d4.
- White is up a pawn.
- Phase: endgam... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 2r5/5pp1/3kp2p/b2p4/P2K1P2/1B1R3P/1PP3P1/8 b - - 2 32
Black to move, move 32.
Move played: Bb6#.
Verdict: Only m... | |
mate | MIT | true | mate_02aa7bf142517b41 | rqb2rk1/1p3ppp/p3pn2/8/P5n1/1P2P2P/NB2BPPN/2RQ1RK1 b - - 0 18 | b7b5 | b5 | By pushing a black pawn forward, it opens up the queenside, granting more freedom to maneuver other pieces. Tactical line: b5 Nxg4 Nxg4 hxg4 Trade the lower value piece for a higher value piece. | null | null | explain_move | club | short | Blunder | {
"fen": "rqb2rk1/5ppp/p3pn2/1p6/P5n1/1P2P2P/NB2BPPN/2RQ1RK1 w - - 0 19",
"pvs": [
{
"score": {
"type": "cp",
"value": 1036
},
"moves": [
"h2g4",
"f6g4",
"e2g4",
"b5a4",
"b3b4",
"e6e5",
"g4c8",
"f8c8",
"c1c... | {
"fen": "rqb2rk1/1p3ppp/p3pn2/8/P5n1/1P2P2P/NB2BPPN/2RQ1RK1 b - - 0 18",
"pvs": [
{
"score": {
"type": "mate",
"value": -1
},
"moves": [
"b8h2"
]
},
{
"score": {
"type": "cp",
"value": 546
},
"moves": [
"g4h2",
... | [
"After b5, White's best reply is Nxg4.",
"After b5, White captures the knight on g4 with Nxg4.",
"White can capture the bishop on c8 with Rxc8.",
"Black threatens Qxh2#.",
"White is up a bishop.",
"Phase: middlegame."
] | task: explain_move
level: club
detail: short
FEN: rqb2rk1/1p3ppp/p3pn2/8/P5n1/1P2P2P/NB2BPPN/2RQ1RK1 b - - 0 18
Black to move, move 18.
Move played: b5.
Verdict: Blunder.
Black's winning chances: 100% → 2%.
Best move: Qxh2#.
Best line: Qxh2#.
Facts:
- After b5, White's best reply is Nxg4.
- After b5, White captures th... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: club
detail: short
FEN: rqb2rk1/1p3ppp/p3pn2/8/P5n1/1P2P2P/NB2BPPN/2RQ1RK1 b - - 0 18
Black to move, move 18.
Move played: b5.
Verdict: Blun... | |
mate | MIT | true | mate_02eb7c8b5567e5e2 | 2r2rk1/1p3ppp/2nbpn2/p2p4/P2P4/2P1B1P1/1qB1QP1P/RN3RK1 w - - 0 16 | c2h7 | Bxh7+ | Sacrifice a piece to unlock a file or diagonal in proximity to the opposing king Tactical line: Bxh7+ Kxh7 Trade the lower value piece for a higher value piece. | null | null | explain_move | club | short | Only move | {
"fen": "2r2rk1/1p3ppB/2nbpn2/p2p4/P2P4/2P1B1P1/1q2QP1P/RN3RK1 b - - 0 16",
"pvs": [
{
"score": {
"type": "cp",
"value": 793
},
"moves": [
"g8h7",
"e2b2",
"c6e7",
"e3c1",
"e7f5",
"b2e2",
"h7g8",
"e2b5",
"f... | {
"fen": "2r2rk1/1p3ppp/2nbpn2/p2p4/P2P4/2P1B1P1/1qB1QP1P/RN3RK1 w - - 0 16",
"pvs": [
{
"score": {
"type": "cp",
"value": 793
},
"moves": [
"c2h7",
"g8h7",
"e2b2",
"c6e7",
"e3c1",
"e7f5",
"b2e2",
"h7g8",
"... | [
"After Bxh7+, Black's best reply is Kxh7.",
"The rook on a1 is not defended.",
"The queen on b2 is not defended.",
"Black can capture the bishop on h7 with Nxh7.",
"Black king is in check on g8.",
"Black is up a pawn in material.",
"Phase: middlegame."
] | task: explain_move
level: club
detail: short
FEN: 2r2rk1/1p3ppp/2nbpn2/p2p4/P2P4/2P1B1P1/1qB1QP1P/RN3RK1 w - - 0 16
White to move, move 16.
Move played: Bxh7+.
Verdict: Only move.
White's winning chances: 95% → 95%.
Best move: Bxh7+.
Best line: Bxh7+ Kxh7 Qxb2 Ne7 Bc1 Nf5.
Facts:
- After Bxh7+, Black's best reply is K... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: club
detail: short
FEN: 2r2rk1/1p3ppp/2nbpn2/p2p4/P2P4/2P1B1P1/1qB1QP1P/RN3RK1 w - - 0 16
White to move, move 16.
Move played: Bxh7+.
Verdic... | |
mate | MIT | true | mate_0348456a47459bf9 | r3k1nr/ppp2ppp/3p4/2b5/2B1Ppbq/2N2N2/PPP3PP/R1BQ1K1R b kq - 4 9 | h4f2 | Qf2# | Reassign the piece to a central area, where it exercises more control over the board. Tactical line: Qf2# Checkmate! | null | null | explain_move | beginner | short | Only move | {
"fen": "r3k1nr/ppp2ppp/3p4/2b5/2B1Ppb1/2N2N2/PPP2qPP/R1BQ1K1R w kq - 5 10",
"pvs": [
{
"score": {
"type": "mate",
"value": -1
},
"moves": []
}
]
} | {
"fen": "r3k1nr/ppp2ppp/3p4/2b5/2B1Ppbq/2N2N2/PPP3PP/R1BQ1K1R b kq - 4 9",
"pvs": [
{
"score": {
"type": "mate",
"value": -1
},
"moves": [
"h4f2"
]
},
{
"score": {
"type": "cp",
"value": 269
},
"moves": [
"h4h5",
... | [
"White king is in check on f1.",
"Black has not castled.",
"White is up a pawn in material.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: r3k1nr/ppp2ppp/3p4/2b5/2B1Ppbq/2N2N2/PPP3PP/R1BQ1K1R b kq - 4 9
Black to move, move 9.
Move played: Qf2#.
Verdict: Only move.
Black's winning chances: 100% → 100%.
Best move: Qf2#.
Best line: Qf2#.
Facts:
- White king is in check on f1.
- Black has not castled.
- W... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: r3k1nr/ppp2ppp/3p4/2b5/2B1Ppbq/2N2N2/PPP3PP/R1BQ1K1R b kq - 4 9
Black to move, move 9.
Move played: Qf2#.
Verdic... | |
mate | MIT | true | mate_03acd396b23ee368 | 6k1/5p1p/3p1Qp1/p1pP3P/2q2P2/8/4r1PK/6R1 w - - 0 32 | h5h6 | h6 | Moving a white pawn forward expands the kingside, offering more avenues for piece movement. Tactical line: h6 Kf8 Qd8+ Re8 Qxd6+ Re7 | null | null | explain_move | beginner | short | Only move | {
"fen": "6k1/5p1p/3p1QpP/p1pP4/2q2P2/8/4r1PK/6R1 b - - 0 32",
"pvs": [
{
"score": {
"type": "cp",
"value": 822
},
"moves": [
"g8f8",
"f6d8",
"e2e8",
"d8d6",
"f8g8",
"d6f6",
"c4d4",
"g1e1",
"e8a8",
... | {
"fen": "6k1/5p1p/3p1Qp1/p1pP3P/2q2P2/8/4r1PK/6R1 w - - 0 32",
"pvs": [
{
"score": {
"type": "cp",
"value": 822
},
"moves": [
"h5h6",
"g8f8",
"f6d8",
"e2e8",
"d8d6",
"f8g8",
"d6f6",
"c4d4",
"g1e1",
... | [
"After h6, Black's best reply is Kf8.",
"Black has a check: Rxg2+.",
"White threatens Qg7#.",
"Black is up two pawns.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 6k1/5p1p/3p1Qp1/p1pP3P/2q2P2/8/4r1PK/6R1 w - - 0 32
White to move, move 32.
Move played: h6.
Verdict: Only move.
White's winning chances: 95% → 95%.
Best move: h6.
Best line: h6 Kf8 Qd8+ Re8 Qxd6+ Kg8.
Facts:
- After h6, Black's best reply is Kf8.
- Black has a che... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 6k1/5p1p/3p1Qp1/p1pP3P/2q2P2/8/4r1PK/6R1 w - - 0 32
White to move, move 32.
Move played: h6.
Verdict: Only move.... | |
mate | MIT | true | mate_044003698e96d61c | 5r2/p4kbp/bp1R2p1/2p1P3/5P2/1PQ3Pq/PB1R3P/6K1 b - - 5 32 | h3f1 | Qf1# | Move the piece to an aggressive spot, enhancing its control over the board. Tactical line: Qf1# Checkmate! | null | null | explain_move | beginner | short | Only move | {
"fen": "5r2/p4kbp/bp1R2p1/2p1P3/5P2/1PQ3P1/PB1R3P/5qK1 w - - 6 33",
"pvs": [
{
"score": {
"type": "mate",
"value": -1
},
"moves": []
}
]
} | {
"fen": "5r2/p4kbp/bp1R2p1/2p1P3/5P2/1PQ3Pq/PB1R3P/6K1 b - - 5 32",
"pvs": [
{
"score": {
"type": "mate",
"value": -1
},
"moves": [
"h3f1"
]
},
{
"score": {
"type": "cp",
"value": 154
},
"moves": [
"g7e5",
... | [
"White king is in check on g1.",
"White is up a minor piece in material.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: 5r2/p4kbp/bp1R2p1/2p1P3/5P2/1PQ3Pq/PB1R3P/6K1 b - - 5 32
Black to move, move 32.
Move played: Qf1#.
Verdict: Only move.
Black's winning chances: 100% → 100%.
Best move: Qf1#.
Best line: Qf1#.
Facts:
- White king is in check on g1.
- White is up a minor piece in mat... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 5r2/p4kbp/bp1R2p1/2p1P3/5P2/1PQ3Pq/PB1R3P/6K1 b - - 5 32
Black to move, move 32.
Move played: Qf1#.
Verdict: Onl... | |
mate | MIT | true | mate_045a36b3c599fa8b | 3r2k1/2q2pbp/2p1b1p1/p3p3/4P3/4BPP1/PQ2BK1P/3R4 w - - 11 31 | e3b6 | Bb6 | Reassign the piece to a central area, where it exercises more control over the board. Tactical line: Bb6 Rb8 Bxc7 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Only move | {
"fen": "3r2k1/2q2pbp/1Bp1b1p1/p3p3/4P3/5PP1/PQ2BK1P/3R4 b - - 12 31",
"pvs": [
{
"score": {
"type": "cp",
"value": 486
},
"moves": [
"d8b8",
"b6c7",
"b8b2",
"d1d8",
"g7f8",
"c7d6",
"b2a2",
"d8f8",
"g8g7",... | {
"fen": "3r2k1/2q2pbp/2p1b1p1/p3p3/4P3/4BPP1/PQ2BK1P/3R4 w - - 11 31",
"pvs": [
{
"score": {
"type": "cp",
"value": 486
},
"moves": [
"e3b6",
"d8b8",
"b6c7",
"b8b2",
"d1d8",
"g7f8",
"c7d6",
"b2a2",
"d8f8",... | [
"Bb6 attacks the queen on c7.",
"After Bb6, Black's best reply is Rb8.",
"The queen on c7 is not defended.",
"Black has a check: Qxb6+.",
"Black can capture the rook on d1 with Rxd1.",
"White threatens Bxc7.",
"Black is up a pawn.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: 3r2k1/2q2pbp/2p1b1p1/p3p3/4P3/4BPP1/PQ2BK1P/3R4 w - - 11 31
White to move, move 31.
Move played: Bb6.
Verdict: Only move.
White's winning chances: 86% → 86%.
Best move: Bb6.
Best line: Bb6 Rb8 Bxc7 Rxb2 Rd8+ Bf8.
Facts:
- Bb6 attacks the queen on c7.
- After Bb6, B... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 3r2k1/2q2pbp/2p1b1p1/p3p3/4P3/4BPP1/PQ2BK1P/3R4 w - - 11 31
White to move, move 31.
Move played: Bb6.
Verdict: O... | |
mate | MIT | true | mate_04710e394c2dec4d | r2r4/ppk2ppp/5b2/3p4/3N1Pb1/P1P5/1P2B1PP/3R1RK1 b - - 4 21 | g4d7 | Bd7 | Move the piece to a pivotal position, providing it with greater board command. Tactical line: Bd7 Rd2 g6 g3 Rac8 Bf3 | null | null | explain_move | beginner | short | Blunder | {
"fen": "r2r4/ppkb1ppp/5b2/3p4/3N1P2/P1P5/1P2B1PP/3R1RK1 w - - 5 22",
"pvs": [
{
"score": {
"type": "cp",
"value": 15
},
"moves": [
"d1d2",
"a8c8"
]
}
]
} | {
"fen": "r2r4/ppk2ppp/5b2/3p4/3N1Pb1/P1P5/1P2B1PP/3R1RK1 b - - 4 21",
"pvs": [
{
"score": {
"type": "cp",
"value": -615
},
"moves": [
"f6d4",
"d1d4",
"g4e2",
"f1e1",
"e2a6",
"c3c4",
"a6c4",
"e1c1",
"a8c8",... | [
"After Bd7, White's best reply is Rd2.",
"White has a check: Nb5+.",
"Material: equal.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: r2r4/ppk2ppp/5b2/3p4/3N1Pb1/P1P5/1P2B1PP/3R1RK1 b - - 4 21
Black to move, move 21.
Move played: Bd7.
Verdict: Blunder.
Black's winning chances: 91% → 49%.
Best move: Bxd4+.
Best line: Bxd4+ Rxd4 Bxe2 Re1 Ba6 c4.
Facts:
- After Bd7, White's best reply is Rd2.
- Whit... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: r2r4/ppk2ppp/5b2/3p4/3N1Pb1/P1P5/1P2B1PP/3R1RK1 b - - 4 21
Black to move, move 21.
Move played: Bd7.
Verdict: Bl... | |
mate | MIT | true | mate_04976e364336ba73 | 3r4/5pk1/5p2/P3pbR1/2P4q/1P2Q3/5P1P/6RK b - - 0 34 | f6g5 | fxg5 | Replace the lower-value piece with a more valuable one to secure an advantage. Tactical line: fxg5 Qxg5+ Qxg5 Rxg5+ Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Only move | {
"fen": "3r4/5pk1/8/P3pbp1/2P4q/1P2Q3/5P1P/6RK w - - 0 35",
"pvs": [
{
"score": {
"type": "cp",
"value": -197
},
"moves": [
"g1g5",
"g7f6",
"e3b6",
"f6g5",
"b6d8",
"f7f6",
"d8d2",
"g5h5",
"f2f3",
"... | {
"fen": "3r4/5pk1/5p2/P3pbR1/2P4q/1P2Q3/5P1P/6RK b - - 0 34",
"pvs": [
{
"score": {
"type": "cp",
"value": -197
},
"moves": [
"f6g5",
"g1g5",
"g7f6",
"e3b6",
"f6g5",
"b6d8",
"f7f6",
"d8d2",
"g5h5",
... | [
"After fxg5, White's best reply is Rxg5+.",
"After fxg5, White captures the pawn on g5 with Rxg5+.",
"White has a check: Rxg5+.",
"Black threatens Qe4+.",
"White is up a minor piece and a pawn in material.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 3r4/5pk1/5p2/P3pbR1/2P4q/1P2Q3/5P1P/6RK b - - 0 34
Black to move, move 34.
Move played: fxg5.
Verdict: Only move.
Black's winning chances: 67% → 67%.
Best move: fxg5.
Best line: fxg5 Rxg5+ Kf6 Qb6+ Kxg5 Qxd8+.
Facts:
- After fxg5, White's best reply is Rxg5+.
- Aft... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 3r4/5pk1/5p2/P3pbR1/2P4q/1P2Q3/5P1P/6RK b - - 0 34
Black to move, move 34.
Move played: fxg5.
Verdict: Only move... | |
mate | MIT | true | mate_04c61ed1065ac5ff | r2qr3/p4p1k/2pp2p1/3p4/3P4/2P1P3/PPQN1n1P/2KR2R1 w - - 2 22 | g1f1 | Rgf1 | Adjust the piece to a key area, where it holds more influence over the board. Tactical line: Rgf1 Nxd1 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Blunder | {
"fen": "r2qr3/p4p1k/2pp2p1/3p4/3P4/2P1P3/PPQN1n1P/2KR1R2 b - - 3 22",
"pvs": [
{
"score": {
"type": "cp",
"value": -178
},
"moves": [
"f2d1",
"f1f7",
"h7h6",
"d2f3",
"d1e3",
"c2f2",
"e8e4",
"h2h4",
"e3f5"... | {
"fen": "r2qr3/p4p1k/2pp2p1/3p4/3P4/2P1P3/PPQN1n1P/2KR2R1 w - - 2 22",
"pvs": [
{
"score": {
"type": "cp",
"value": 539
},
"moves": [
"d1f1",
"e8e3",
"f1f2",
"d8e7",
"c2d1",
"a8e8",
"d2f3",
"e3e2",
"f2e2",... | [
"Rgf1 attacks the knight on f2.",
"After Rgf1, Black's best reply is Nxd1.",
"The knight on f2 is not defended.",
"Black has a check: Nd3+.",
"Black can capture the rook on d1 with Nxd1.",
"White threatens Rxf2.",
"Material: equal.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: r2qr3/p4p1k/2pp2p1/3p4/3P4/2P1P3/PPQN1n1P/2KR2R1 w - - 2 22
White to move, move 22.
Move played: Rgf1.
Verdict: Blunder.
White's winning chances: 88% → 34%.
Best move: Rdf1.
Best line: Rdf1 Rxe3 Rxf2 Qe7 Qd1 Re8.
Facts:
- Rgf1 attacks the knight on f2.
- After Rgf1... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: r2qr3/p4p1k/2pp2p1/3p4/3P4/2P1P3/PPQN1n1P/2KR2R1 w - - 2 22
White to move, move 22.
Move played: Rgf1.
Verdict: ... | |
mate | MIT | true | mate_0595fcf41b9c4bf0 | 7k/p2q3p/1p6/1N2p2r/PP3nRp/5P2/Q4P1K/8 w - - 0 37 | g4g8 | Rg8# | Relocate the piece to a dynamic square, it's more influential on the board. Tactical line: Rg8# Checkmate! | null | null | explain_move | beginner | short | Best | {
"fen": "6Rk/p2q3p/1p6/1N2p2r/PP3n1p/5P2/Q4P1K/8 b - - 1 37",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": []
}
]
} | {
"fen": "7k/p2q3p/1p6/1N2p2r/PP3nRp/5P2/Q4P1K/8 w - - 0 37",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": [
"g4g8"
]
},
{
"score": {
"type": "mate",
"value": 1
},
"moves": [
"a2g8"
]
},
... | [
"Black king is in check on h8.",
"Black is up a pawn.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 7k/p2q3p/1p6/1N2p2r/PP3nRp/5P2/Q4P1K/8 w - - 0 37
White to move, move 37.
Move played: Rg8#.
Verdict: Best.
White's winning chances: 100% → 100%.
Best move: Rg8#.
Best line: Rg8#.
Facts:
- Black king is in check on h8.
- Black is up a pawn.
- Phase: endgame. | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 7k/p2q3p/1p6/1N2p2r/PP3nRp/5P2/Q4P1K/8 w - - 0 37
White to move, move 37.
Move played: Rg8#.
Verdict: Best.
Whit... | |
mate | MIT | true | mate_059999538d87f465 | 2k5/ppp5/3b2Q1/7p/8/6PP/P4P1K/3q4 w - - 1 28 | g6e8 | Qe8# | Reposition the piece to an assertive square, where it governs more of the board. Tactical line: Qe8# Checkmate! | null | null | explain_move | beginner | short | Only move | {
"fen": "2k1Q3/ppp5/3b4/7p/8/6PP/P4P1K/3q4 b - - 2 28",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": []
}
]
} | {
"fen": "2k5/ppp5/3b2Q1/7p/8/6PP/P4P1K/3q4 w - - 1 28",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": [
"g6e8"
]
},
{
"score": {
"type": "cp",
"value": -512
},
"moves": [
"g6e6",
"c8d8",
... | [
"Black king is in check on c8.",
"Black is up a bishop.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 2k5/ppp5/3b2Q1/7p/8/6PP/P4P1K/3q4 w - - 1 28
White to move, move 28.
Move played: Qe8#.
Verdict: Only move.
White's winning chances: 100% → 100%.
Best move: Qe8#.
Best line: Qe8#.
Facts:
- Black king is in check on c8.
- Black is up a bishop.
- Phase: endgame. | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 2k5/ppp5/3b2Q1/7p/8/6PP/P4P1K/3q4 w - - 1 28
White to move, move 28.
Move played: Qe8#.
Verdict: Only move.
Whit... | |
mate | MIT | true | mate_05bae00fe6bb9e20 | 6k1/pp1nbppp/2q1p3/3p1b2/3P4/1Pr1PNB1/P3BPPP/Q4RK1 w - - 2 18 | e2b5 | Bb5 | Plant the piece in a dominant spot, expanding its control over the board. Tactical line: Bb5 Qxb5 Qxc3 Ba3 Qc8+ Nf8 | null | null | explain_move | beginner | short | Only move | {
"fen": "6k1/pp1nbppp/2q1p3/1B1p1b2/3P4/1Pr1PNB1/P4PPP/Q4RK1 b - - 3 18",
"pvs": [
{
"score": {
"type": "cp",
"value": 531
},
"moves": [
"c6b5",
"a1c3",
"e7b4",
"c3c7",
"d7f8",
"g3d6",
"f5d3"
]
}
]
} | {
"fen": "6k1/pp1nbppp/2q1p3/3p1b2/3P4/1Pr1PNB1/P3BPPP/Q4RK1 w - - 2 18",
"pvs": [
{
"score": {
"type": "cp",
"value": 531
},
"moves": [
"e2b5",
"c6b5",
"a1c3",
"e7b4",
"c3c7",
"d7f8",
"g3d6",
"f5d3"
]
},... | [
"Bb5 attacks the queen on c6.",
"After Bb5, Black's best reply is Qxb5.",
"The bishop on b5 is not defended.",
"Black can capture the bishop on b5 with Qxb5.",
"White threatens Bxc6.",
"Material: equal.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: 6k1/pp1nbppp/2q1p3/3p1b2/3P4/1Pr1PNB1/P3BPPP/Q4RK1 w - - 2 18
White to move, move 18.
Move played: Bb5.
Verdict: Only move.
White's winning chances: 88% → 88%.
Best move: Bb5.
Best line: Bb5 Qxb5 Qxc3 Bb4 Qc7 Nf8.
Facts:
- Bb5 attacks the queen on c6.
- After Bb5, ... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 6k1/pp1nbppp/2q1p3/3p1b2/3P4/1Pr1PNB1/P3BPPP/Q4RK1 w - - 2 18
White to move, move 18.
Move played: Bb5.
Verdict:... | |
mate | MIT | true | mate_061cfab73cc63403 | 5rk1/pp2b1pp/2B3q1/3pp3/4b3/2P4P/PP3PP1/R1BQR1K1 b - - 0 20 | g6g2 | Qxg2# | Sacrifice a piece to open a channel or diagonal near the opponent's king Tactical line: Qxg2# Checkmate! | null | null | explain_move | club | short | Only move | {
"fen": "5rk1/pp2b1pp/2B5/3pp3/4b3/2P4P/PP3Pq1/R1BQR1K1 w - - 0 21",
"pvs": [
{
"score": {
"type": "mate",
"value": -1
},
"moves": []
}
]
} | {
"fen": "5rk1/pp2b1pp/2B3q1/3pp3/4b3/2P4P/PP3PP1/R1BQR1K1 b - - 0 20",
"pvs": [
{
"score": {
"type": "mate",
"value": -1
},
"moves": [
"g6g2"
]
},
{
"score": {
"type": "cp",
"value": 64
},
"moves": [
"b7c6",
... | [
"The bishop on c6 is not defended.",
"White king is in check on g1.",
"White is up a rook.",
"Phase: middlegame."
] | task: explain_move
level: club
detail: short
FEN: 5rk1/pp2b1pp/2B3q1/3pp3/4b3/2P4P/PP3PP1/R1BQR1K1 b - - 0 20
Black to move, move 20.
Move played: Qxg2#.
Verdict: Only move.
Black's winning chances: 100% → 100%.
Best move: Qxg2#.
Best line: Qxg2#.
Facts:
- The bishop on c6 is not defended.
- White king is in check on ... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: club
detail: short
FEN: 5rk1/pp2b1pp/2B3q1/3pp3/4b3/2P4P/PP3PP1/R1BQR1K1 b - - 0 20
Black to move, move 20.
Move played: Qxg2#.
Verdict: Onl... | |
mate | MIT | true | mate_0699f8f1c5b49ee2 | 5k2/R4pp1/3P4/7p/2K5/7r/8/8 w - - 1 31 | a7a8 | Ra8# | Navigate the piece to an advanced spot, augmenting its influence over the board. Tactical line: Ra8# Checkmate! | null | null | explain_move | beginner | short | Only move | {
"fen": "R4k2/5pp1/3P4/7p/2K5/7r/8/8 b - - 2 31",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": []
}
]
} | {
"fen": "5k2/R4pp1/3P4/7p/2K5/7r/8/8 w - - 1 31",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": [
"a7a8"
]
},
{
"score": {
"type": "cp",
"value": 12
},
"moves": [
"c4c5",
"h3e3",
"c5... | [
"Black king is in check on f8.",
"Black is up two pawns.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 5k2/R4pp1/3P4/7p/2K5/7r/8/8 w - - 1 31
White to move, move 31.
Move played: Ra8#.
Verdict: Only move.
White's winning chances: 100% → 100%.
Best move: Ra8#.
Best line: Ra8#.
Facts:
- Black king is in check on f8.
- Black is up two pawns.
- Phase: endgame. | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 5k2/R4pp1/3P4/7p/2K5/7r/8/8 w - - 1 31
White to move, move 31.
Move played: Ra8#.
Verdict: Only move.
White's wi... | |
mate | MIT | true | mate_06bfcd4a9adf5852 | 2r5/k1qr1pp1/p4b1p/2pQp3/2P5/2P4P/4R1P1/1R4BK w - - 4 33 | g1h2 | Bh2 | Reposition the piece to an assertive square, where it governs more of the board. Tactical line: Bh2 Rxd5 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Blunder | {
"fen": "2r5/k1qr1pp1/p4b1p/2pQp3/2P5/2P4P/4R1PB/1R5K b - - 5 33",
"pvs": [
{
"score": {
"type": "cp",
"value": -609
},
"moves": [
"d7d5",
"c4d5",
"c8b8",
"e2b2",
"b8b2",
"b1b2",
"c7c8",
"h2g1",
"e5e4"
... | {
"fen": "2r5/k1qr1pp1/p4b1p/2pQp3/2P5/2P4P/4R1P1/1R4BK w - - 4 33",
"pvs": [
{
"score": {
"type": "cp",
"value": 464
},
"moves": [
"g1c5",
"c7c5",
"d5d7",
"c5c7",
"d7d1",
"f6e7",
"e2d2",
"c7c4"
]
},
... | [
"Bh2 attacks the pawn on e5 together with the rook on e2.",
"After Bh2, Black's best reply is Rxd5.",
"Black can capture the queen on d5 with Rxd5.",
"White threatens Rb7+.",
"Black is up two pawns.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: 2r5/k1qr1pp1/p4b1p/2pQp3/2P5/2P4P/4R1P1/1R4BK w - - 4 33
White to move, move 33.
Move played: Bh2.
Verdict: Blunder.
White's winning chances: 85% → 10%.
Best move: Bxc5+.
Best line: Bxc5+ Qxc5 Qxd7+ Qc7 Qd1 Be7.
Facts:
- Bh2 attacks the pawn on e5 together with the... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 2r5/k1qr1pp1/p4b1p/2pQp3/2P5/2P4P/4R1P1/1R4BK w - - 4 33
White to move, move 33.
Move played: Bh2.
Verdict: Blun... | |
mate | MIT | true | mate_07335c5f7e225554 | rn1q1rk1/1b1pnpbp/pp4p1/2p5/P1B1p2Q/2NP1N2/1PP3PP/R1B2RK1 w - - 0 12 | f3g5 | Ng5 | Adjust the piece to a key area, where it holds more influence over the board. Tactical line: Ng5 Bd4+ Kh1 h5 Bxf7+ Kh8 | null | null | explain_move | beginner | short | Only move | {
"fen": "rn1q1rk1/1b1pnpbp/pp4p1/2p3N1/P1B1p2Q/2NP4/1PP3PP/R1B2RK1 b - - 1 12",
"pvs": [
{
"score": {
"type": "cp",
"value": 450
},
"moves": [
"g7d4",
"g1h1",
"h7h5",
"c4f7",
"g8g7",
"c3e4",
"b7e4",
"d3e4",
... | {
"fen": "rn1q1rk1/1b1pnpbp/pp4p1/2p5/P1B1p2Q/2NP1N2/1PP3PP/R1B2RK1 w - - 0 12",
"pvs": [
{
"score": {
"type": "cp",
"value": 450
},
"moves": [
"f3g5",
"g7d4",
"g1h1",
"h7h5",
"c4f7",
"g8g7",
"c3e4",
"b7e4",
... | [
"Ng5 attacks the pawn on e4 together with the knight on c3.",
"After Ng5, Black's best reply is Bd4+.",
"Black has a check: Bd4+.",
"Black can capture the knight on c3 with Bxc3.",
"White threatens Qxh7#.",
"Black is up two pawns.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: rn1q1rk1/1b1pnpbp/pp4p1/2p5/P1B1p2Q/2NP1N2/1PP3PP/R1B2RK1 w - - 0 12
White to move, move 12.
Move played: Ng5.
Verdict: Only move.
White's winning chances: 84% → 84%.
Best move: Ng5.
Best line: Ng5 Bd4+ Kh1 h5 Bxf7+ Kg7.
Facts:
- Ng5 attacks the pawn on e4 together... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: rn1q1rk1/1b1pnpbp/pp4p1/2p5/P1B1p2Q/2NP1N2/1PP3PP/R1B2RK1 w - - 0 12
White to move, move 12.
Move played: Ng5.
V... | |
mate | MIT | true | mate_0766610f00253c7a | 2kr4/1pp1q1bQ/p3R3/5pp1/3P2P1/1BP2P2/PP5P/6K1 b - - 0 27 | d8d7 | Rd7 | Switch the piece to a more advantageous place, increasing its mastery over the board. Tactical line: Rd7 Rxe7 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Blunder | {
"fen": "2k5/1pprq1bQ/p3R3/5pp1/3P2P1/1BP2P2/PP5P/6K1 w - - 1 28",
"pvs": [
{
"score": {
"type": "cp",
"value": 817
},
"moves": [
"e6e7",
"d7e7",
"h7g8",
"c8d7",
"g8d5",
"d7e8",
"b3a4",
"b7b5",
"d5a8",
... | {
"fen": "2kr4/1pp1q1bQ/p3R3/5pp1/3P2P1/1BP2P2/PP5P/6K1 b - - 0 27",
"pvs": [
{
"score": {
"type": "cp",
"value": -664
},
"moves": [
"g7d4",
"g1h1",
"e7h7",
"b3c2",
"d8h8",
"e6e8",
"h8e8",
"c2f5",
"h7f5"
... | [
"Rd7 attacks the pawn on d4 together with the bishop on g7.",
"After Rd7, White's best reply is Rxe7.",
"White has a check: Qg8+.",
"White can capture the queen on e7 with Rxe7.",
"Black threatens Bxd4+.",
"White is up two pawns.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 2kr4/1pp1q1bQ/p3R3/5pp1/3P2P1/1BP2P2/PP5P/6K1 b - - 0 27
Black to move, move 27.
Move played: Rd7.
Verdict: Blunder.
Black's winning chances: 92% → 5%.
Best move: Bxd4+.
Best line: Bxd4+ Kh1 Qxh7 Bc2 Rh8 Re8+.
Facts:
- Rd7 attacks the pawn on d4 together with the b... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 2kr4/1pp1q1bQ/p3R3/5pp1/3P2P1/1BP2P2/PP5P/6K1 b - - 0 27
Black to move, move 27.
Move played: Rd7.
Verdict: Blun... | |
mate | MIT | true | mate_07c8ff938e0e4362 | r7/6Q1/p6p/3q3p/1P2pR2/7k/8/7K w - - 10 43 | g7f6 | Qf6 | Settle the piece in a more energetic spot, where it has better board supervision. Tactical line: Qf6 Qg5 Qe6+ Kg3 Rxe4 Rf8 | null | null | explain_move | beginner | short | Blunder | {
"fen": "r7/8/p4Q1p/3q3p/1P2pR2/7k/8/7K b - - 11 43",
"pvs": [
{
"score": {
"type": "cp",
"value": 11
},
"moves": [
"d5d1",
"f4f1",
"d1g4",
"f6c3",
"h3h4",
"c3e1",
"h4h3",
"e1f2",
"g4f3",
"f2f3",
... | {
"fen": "r7/6Q1/p6p/3q3p/1P2pR2/7k/8/7K w - - 10 43",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": [
"g7g2"
]
},
{
"score": {
"type": "cp",
"value": 11
},
"moves": [
"g7f6",
"d5d1",
... | [
"After Qf6, Black's best reply is Qd1+.",
"Black has a check: e3+.",
"White threatens Qh4#.",
"Black is up a minor piece in material.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: r7/6Q1/p6p/3q3p/1P2pR2/7k/8/7K w - - 10 43
White to move, move 43.
Move played: Qf6.
Verdict: Blunder.
White's winning chances: 100% → 51%.
Best move: Qg2#.
Best line: Qg2#.
Facts:
- After Qf6, Black's best reply is Qd1+.
- Black has a check: e3+.
- White threatens... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: r7/6Q1/p6p/3q3p/1P2pR2/7k/8/7K w - - 10 43
White to move, move 43.
Move played: Qf6.
Verdict: Blunder.
White's w... | |
mate | MIT | true | mate_0850567664f81cb2 | r4rk1/1p4p1/1p2q2p/3p4/1Pp2P2/P5P1/2n3BP/R2Q3K w - - 0 21 | g2f3 | Bf3 | Relocate the piece to a dynamic square, it's more influential on the board. Tactical line: Bf3 Ne3 Qd2 d4 b5 Qf6 | null | null | explain_move | beginner | short | Blunder | {
"fen": "r4rk1/1p4p1/1p2q2p/3p4/1Pp2P2/P4BP1/2n4P/R2Q3K b - - 1 21",
"pvs": [
{
"score": {
"type": "cp",
"value": -787
},
"moves": [
"c2e3",
"d1e2",
"d5d4",
"f3g2",
"c4c3"
]
}
]
} | {
"fen": "r4rk1/1p4p1/1p2q2p/3p4/1Pp2P2/P5P1/2n3BP/R2Q3K w - - 0 21",
"pvs": [
{
"score": {
"type": "cp",
"value": 187
},
"moves": [
"g2d5",
"e6d5",
"d1d5",
"g8h8",
"a1c1",
"c2e3",
"d5e4",
"f8e8",
"e4b7",
... | [
"Bf3 attacks the pawn on d5 together with the queen on d1.",
"After Bf3, Black's best reply is Ne3.",
"The knight on c2 is not defended.",
"Black has a check: Qe1+.",
"Black can capture the rook on a1 with Nxa1.",
"White threatens Qxc2.",
"Black is up two minor pieces in material.",
"Phase: middlegame... | task: explain_move
level: beginner
detail: short
FEN: r4rk1/1p4p1/1p2q2p/3p4/1Pp2P2/P5P1/2n3BP/R2Q3K w - - 0 21
White to move, move 21.
Move played: Bf3.
Verdict: Blunder.
White's winning chances: 67% → 5%.
Best move: Bxd5.
Best line: Bxd5 Qxd5+ Qxd5+ Kh8 Rc1 Ne3.
Facts:
- Bf3 attacks the pawn on d5 together with the ... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: r4rk1/1p4p1/1p2q2p/3p4/1Pp2P2/P5P1/2n3BP/R2Q3K w - - 0 21
White to move, move 21.
Move played: Bf3.
Verdict: Blu... | |
mate | MIT | true | mate_08670cf93e16e7f3 | 2r3k1/5pb1/6p1/pr6/1p1p2Q1/1P3P2/nKP3P1/3R3R b - - 1 29 | d4d3 | d3+ | A forward move by a black pawn opens up the center, resulting in greater freedom to reposition pieces. Tactical line: d3+ Kxa2 Trade the lower value piece for a higher value piece. | null | null | explain_move | club | short | Only move | {
"fen": "2r3k1/5pb1/6p1/pr6/1p4Q1/1P1p1P2/nKP3P1/3R3R w - - 0 30",
"pvs": [
{
"score": {
"type": "cp",
"value": -403
},
"moves": [
"c2c3",
"c8c3",
"b2a2",
"c3c2",
"a2b1",
"c2b2",
"b1c1",
"b5c5",
"g4c4",
... | {
"fen": "2r3k1/5pb1/6p1/pr6/1p1p2Q1/1P3P2/nKP3P1/3R3R b - - 1 29",
"pvs": [
{
"score": {
"type": "cp",
"value": -403
},
"moves": [
"d4d3",
"c2c3",
"c8c3",
"b2a2",
"c3c2",
"a2b1",
"c2b2",
"b1c1",
"b5c5",
... | [
"After d3+, White's best reply is c3.",
"After c3, White wins the knight on a2.",
"The knight on a2 is not defended.",
"The rook on c8 is not defended.",
"White can capture the knight on a2 with Kxa2.",
"White king is in check on b2.",
"White is up two pawns in material.",
"Phase: middlegame."
] | task: explain_move
level: club
detail: short
FEN: 2r3k1/5pb1/6p1/pr6/1p1p2Q1/1P3P2/nKP3P1/3R3R b - - 1 29
Black to move, move 29.
Move played: d3+.
Verdict: Only move.
Black's winning chances: 82% → 82%.
Best move: d3+.
Best line: d3+ c3 Rxc3 Kxa2 Rc2+ Kb1.
Facts:
- After d3+, White's best reply is c3.
- After c3, Whi... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: club
detail: short
FEN: 2r3k1/5pb1/6p1/pr6/1p1p2Q1/1P3P2/nKP3P1/3R3R b - - 1 29
Black to move, move 29.
Move played: d3+.
Verdict: Only move... | |
mate | MIT | true | mate_08785c605a4bc7ba | 2r4k/Q7/R1r5/1p2p2q/1P1p4/3P3P/5R1K/8 b - - 0 40 | h5h4 | Qh4 | Set the piece in a more potent location, giving it superior board control. Tactical line: Qh4 Qf7 Rxa6 Qf5 Re8 Rf1 | null | null | explain_move | beginner | short | Only move | {
"fen": "2r4k/Q7/R1r5/1p2p3/1P1p3q/3P3P/5R1K/8 w - - 1 41",
"pvs": [
{
"score": {
"type": "cp",
"value": -793
},
"moves": [
"a7f7",
"c6a6",
"f7f5",
"c8g8",
"f5e5",
"h8h7",
"e5e4",
"h4e4",
"d3e4",
"... | {
"fen": "2r4k/Q7/R1r5/1p2p2q/1P1p4/3P3P/5R1K/8 b - - 0 40",
"pvs": [
{
"score": {
"type": "cp",
"value": -793
},
"moves": [
"h5h4",
"a7f7",
"c6a6",
"f7f5",
"c8g8",
"f5e5",
"h8h7",
"e5e4",
"h4e4",
"... | [
"Qh4 attacks the rook on f2.",
"After Qh4, White's best reply is Qf7.",
"The rook on f2 is not defended.",
"White has a check: Rf8+.",
"White can capture the rook on c6 with Rxc6.",
"Black threatens Qxf2+.",
"Material: equal.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 2r4k/Q7/R1r5/1p2p2q/1P1p4/3P3P/5R1K/8 b - - 0 40
Black to move, move 40.
Move played: Qh4.
Verdict: Only move.
Black's winning chances: 95% → 95%.
Best move: Qh4.
Best line: Qh4 Qf7 Rxa6 Qf5 Rg8 Qxe5+.
Facts:
- Qh4 attacks the rook on f2.
- After Qh4, White's best ... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 2r4k/Q7/R1r5/1p2p2q/1P1p4/3P3P/5R1K/8 b - - 0 40
Black to move, move 40.
Move played: Qh4.
Verdict: Only move.
B... | |
mate | MIT | true | mate_08e8379534b4d3b1 | 3r3k/ppp3pp/2b5/5p2/3qpN2/1Q4R1/PPP3PP/3r1R1K w - - 17 25 | f4g6 | Ng6+ | Displace the piece to a more promising position, strengthening its board authority. Tactical line: Ng6+ hxg6 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Only move | {
"fen": "3r3k/ppp3pp/2b3N1/5p2/3qp3/1Q4R1/PPP3PP/3r1R1K b - - 18 25",
"pvs": [
{
"score": {
"type": "mate",
"value": 2
},
"moves": [
"h7g6",
"g3h3"
]
}
]
} | {
"fen": "3r3k/ppp3pp/2b5/5p2/3qpN2/1Q4R1/PPP3PP/3r1R1K w - - 17 25",
"pvs": [
{
"score": {
"type": "mate",
"value": 2
},
"moves": [
"f4g6",
"h7g6",
"g3h3"
]
},
{
"score": {
"type": "cp",
"value": -1147
},
... | [
"After Ng6+, Black's best reply is hxg6.",
"After Ng6+, Black captures the knight on g6 with hxg6.",
"The rook on f1 is not defended.",
"Black can capture the knight on g6 with hxg6.",
"Black king is in check on h8.",
"Black is up two pawns in material.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: 3r3k/ppp3pp/2b5/5p2/3qpN2/1Q4R1/PPP3PP/3r1R1K w - - 17 25
White to move, move 25.
Move played: Ng6+.
Verdict: Only move.
White's winning chances: 100% → 100%.
Best move: Ng6+.
Best line: Ng6+ hxg6 Rh3#.
Facts:
- After Ng6+, Black's best reply is hxg6.
- After Ng6+,... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 3r3k/ppp3pp/2b5/5p2/3qpN2/1Q4R1/PPP3PP/3r1R1K w - - 17 25
White to move, move 25.
Move played: Ng6+.
Verdict: On... | |
mate | MIT | true | mate_08fdc5836861541f | 5r1k/6pp/3p2q1/1p1Ppr2/3p1P2/6P1/1PP1QR1P/5RK1 w - - 2 26 | f4e5 | fxe5 | Capturing another pawn, the pawn transforms the structure. Tactical line: fxe5 dxe5 Qxe5 Rxf2 Rxf2 Kg8 | null | null | explain_move | beginner | short | Best | {
"fen": "5r1k/6pp/3p2q1/1p1PPr2/3p4/6P1/1PP1QR1P/5RK1 b - - 0 26",
"pvs": [
{
"score": {
"type": "cp",
"value": 198
},
"moves": [
"d6e5",
"f2f5",
"f8f5",
"f1f5",
"g6f5",
"e2b5",
"h7h6"
]
}
]
} | {
"fen": "5r1k/6pp/3p2q1/1p1Ppr2/3p1P2/6P1/1PP1QR1P/5RK1 w - - 2 26",
"pvs": [
{
"score": {
"type": "cp",
"value": 198
},
"moves": [
"f4e5",
"d6e5",
"f2f5",
"f8f5",
"f1f5",
"g6f5",
"e2b5",
"h7h6"
]
},
... | [
"After fxe5, Black's best reply is dxe5.",
"After fxe5, Black captures the pawn on e5 with dxe5.",
"Black has a check: Qxg3+.",
"Black can capture the rook on f2 with Rxf2.",
"Material: equal.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 5r1k/6pp/3p2q1/1p1Ppr2/3p1P2/6P1/1PP1QR1P/5RK1 w - - 2 26
White to move, move 26.
Move played: fxe5.
Verdict: Best.
White's winning chances: 67% → 67%.
Best move: fxe5.
Best line: fxe5 dxe5 Rxf5 Rxf5 Rxf5 Qxf5.
Facts:
- After fxe5, Black's best reply is dxe5.
- Aft... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 5r1k/6pp/3p2q1/1p1Ppr2/3p1P2/6P1/1PP1QR1P/5RK1 w - - 2 26
White to move, move 26.
Move played: fxe5.
Verdict: Be... | |
mate | MIT | true | mate_097d098b8b91dfa3 | 8/k4ppp/1p6/1P6/P4P2/7n/6PP/2R3RK b - - 0 33 | h3f2 | Nf2# | Move the piece to a pivotal position, providing it with greater board command. Tactical line: Nf2# Checkmate! | null | null | explain_move | beginner | short | Only move | {
"fen": "8/k4ppp/1p6/1P6/P4P2/8/5nPP/2R3RK w - - 1 34",
"pvs": [
{
"score": {
"type": "mate",
"value": -1
},
"moves": []
}
]
} | {
"fen": "8/k4ppp/1p6/1P6/P4P2/7n/6PP/2R3RK b - - 0 33",
"pvs": [
{
"score": {
"type": "mate",
"value": -1
},
"moves": [
"h3f2"
]
},
{
"score": {
"type": "cp",
"value": 754
},
"moves": [
"g7g6",
"g2h3",
... | [
"White king is in check on h1.",
"White is up a rook and a minor piece in material.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 8/k4ppp/1p6/1P6/P4P2/7n/6PP/2R3RK b - - 0 33
Black to move, move 33.
Move played: Nf2#.
Verdict: Only move.
Black's winning chances: 100% → 100%.
Best move: Nf2#.
Best line: Nf2#.
Facts:
- White king is in check on h1.
- White is up a rook and a minor piece in mate... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 8/k4ppp/1p6/1P6/P4P2/7n/6PP/2R3RK b - - 0 33
Black to move, move 33.
Move played: Nf2#.
Verdict: Only move.
Blac... | |
mate | MIT | true | mate_0986083b37266ddc | r1b2rk1/p1pq1ppp/2p2P2/3pPR2/6P1/7Q/PbP4P/RN4K1 w - - 1 18 | b1d2 | Nd2 | Move the piece to a stronger position, enhancing its board control. Tactical line: Nd2 Bxa1 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Blunder | {
"fen": "r1b2rk1/p1pq1ppp/2p2P2/3pPR2/6P1/7Q/PbPN3P/R5K1 b - - 2 18",
"pvs": [
{
"score": {
"type": "cp",
"value": -237
},
"moves": [
"b2e5",
"f5e5",
"g7f6",
"e5f5",
"d7e7",
"f5h5",
"e7c5",
"g1h1",
"c5c2",... | {
"fen": "r1b2rk1/p1pq1ppp/2p2P2/3pPR2/6P1/7Q/PbP4P/RN4K1 w - - 1 18",
"pvs": [
{
"score": {
"type": "cp",
"value": 188
},
"moves": [
"f5g5",
"b2d4",
"g1h1",
"g7g6",
"h3h6",
"d4a1"
]
},
{
"score": {
"ty... | [
"After Nd2, Black's best reply is Bxe5.",
"The rook on a1 is not defended.",
"Black has a check: Bd4+.",
"Black can capture the rook on a1 with Bxa1.",
"Black is up a minor piece and a pawn in material.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: r1b2rk1/p1pq1ppp/2p2P2/3pPR2/6P1/7Q/PbP4P/RN4K1 w - - 1 18
White to move, move 18.
Move played: Nd2.
Verdict: Blunder.
White's winning chances: 67% → 29%.
Best move: Rg5.
Best line: Rg5 Bd4+ Kh1 g6 Qh6 Bxa1.
Facts:
- After Nd2, Black's best reply is Bxe5.
- The roo... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: r1b2rk1/p1pq1ppp/2p2P2/3pPR2/6P1/7Q/PbP4P/RN4K1 w - - 1 18
White to move, move 18.
Move played: Nd2.
Verdict: Bl... | |
mate | MIT | true | mate_09ac888e7f65dee7 | 4b3/4kp1R/3np1B1/4N2P/1P2PP2/KP6/6r1/8 b - - 0 44 | d6b5 | Nb5+ | Navigate the piece to an advanced spot, augmenting its influence over the board. Tactical line: Nb5+ Ka4 Ra2# Checkmate! | null | null | explain_move | beginner | short | Only move | {
"fen": "4b3/4kp1R/4p1B1/1n2N2P/1P2PP2/KP6/6r1/8 w - - 1 45",
"pvs": [
{
"score": {
"type": "mate",
"value": -2
},
"moves": [
"a3a4",
"g2a2"
]
}
]
} | {
"fen": "4b3/4kp1R/3np1B1/4N2P/1P2PP2/KP6/6r1/8 b - - 0 44",
"pvs": [
{
"score": {
"type": "mate",
"value": -2
},
"moves": [
"d6b5",
"a3a4",
"g2a2"
]
},
{
"score": {
"type": "cp",
"value": 77
},
"moves": [... | [
"After Nb5+, White's best reply is Ka4.",
"White king is in check on a3.",
"White is up a minor piece in material.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 4b3/4kp1R/3np1B1/4N2P/1P2PP2/KP6/6r1/8 b - - 0 44
Black to move, move 44.
Move played: Nb5+.
Verdict: Only move.
Black's winning chances: 100% → 100%.
Best move: Nb5+.
Best line: Nb5+ Ka4 Ra2#.
Facts:
- After Nb5+, White's best reply is Ka4.
- White king is in chec... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 4b3/4kp1R/3np1B1/4N2P/1P2PP2/KP6/6r1/8 b - - 0 44
Black to move, move 44.
Move played: Nb5+.
Verdict: Only move.... | |
mate | MIT | true | mate_09d52e20a3f85b9c | 1r2k2r/p3bp1p/3qb3/3pNnp1/N2P1p2/1P5P/PB4P1/2RQ1RK1 w k - 8 18 | c1c6 | Rc6 | Reassign the piece to a central area, where it exercises more control over the board. Tactical line: Rc6 Ne3 Qe2 O-O Rxd6 Trade the lower value piece for a higher value piece. | null | null | explain_move | club | short | Only move | {
"fen": "1r2k2r/p3bp1p/2Rqb3/3pNnp1/N2P1p2/1P5P/PB4P1/3Q1RK1 b k - 9 18",
"pvs": [
{
"score": {
"type": "cp",
"value": 295
},
"moves": [
"f5e3",
"d1h5",
"e3f1",
"g1f1",
"d6b4",
"c6e6",
"e8g8",
"e6h6",
"b4d... | {
"fen": "1r2k2r/p3bp1p/3qb3/3pNnp1/N2P1p2/1P5P/PB4P1/2RQ1RK1 w k - 8 18",
"pvs": [
{
"score": {
"type": "cp",
"value": 295
},
"moves": [
"c1c6",
"f5e3",
"d1h5",
"e3f1",
"g1f1",
"d6b4",
"c6e6",
"e8g8",
"e6h... | [
"Rc6 attacks the queen on d6.",
"After Rc6, Black's best reply is Ne3.",
"After Ne3, Black wins the rook on f1.",
"Black can capture the rook on c6 with Qxc6.",
"White threatens Rxd6.",
"Black has not castled.",
"Black is up a pawn in material.",
"Phase: middlegame."
] | task: explain_move
level: club
detail: short
FEN: 1r2k2r/p3bp1p/3qb3/3pNnp1/N2P1p2/1P5P/PB4P1/2RQ1RK1 w k - 8 18
White to move, move 18.
Move played: Rc6.
Verdict: Only move.
White's winning chances: 75% → 75%.
Best move: Rc6.
Best line: Rc6 Ne3 Qh5 Nxf1 Kxf1 Qb4.
Facts:
- Rc6 attacks the queen on d6.
- After Rc6, Bla... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: club
detail: short
FEN: 1r2k2r/p3bp1p/3qb3/3pNnp1/N2P1p2/1P5P/PB4P1/2RQ1RK1 w k - 8 18
White to move, move 18.
Move played: Rc6.
Verdict: On... | |
mate | MIT | true | mate_09e8df6b6cb4c169 | 4r1k1/p4p2/7p/6p1/2R5/P4P2/1PnBr1PP/3R1K2 b - - 1 23 | c2e3 | Ne3+ | Navigate the piece to an advanced spot, augmenting its influence over the board. Tactical line: Ne3+ Kxe2 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Blunder | {
"fen": "4r1k1/p4p2/7p/6p1/2R5/P3nP2/1P1Br1PP/3R1K2 w - - 2 24",
"pvs": [
{
"score": {
"type": "cp",
"value": 64
},
"moves": [
"d2e3",
"e8e3",
"c4d4",
"e2c2",
"d4d2",
"c2c6",
"d2d6",
"c6c2",
"d1d2",
... | {
"fen": "4r1k1/p4p2/7p/6p1/2R5/P4P2/1PnBr1PP/3R1K2 b - - 1 23",
"pvs": [
{
"score": {
"type": "cp",
"value": -500
},
"moves": [
"e2d2",
"d1d2",
"c2e3",
"f1g1",
"e3c4",
"d2c2",
"c4b6",
"c2c7",
"e8e1",
... | [
"After Ne3+, White's best reply is Bxe3.",
"The rook on d1 is not defended.",
"The rook on e2 is not defended.",
"White can capture the rook on e2 with Kxe2.",
"White king is in check on f1.",
"White is up a pawn in material.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 4r1k1/p4p2/7p/6p1/2R5/P4P2/1PnBr1PP/3R1K2 b - - 1 23
Black to move, move 23.
Move played: Ne3+.
Verdict: Blunder.
Black's winning chances: 86% → 44%.
Best move: Rxd2.
Best line: Rxd2 Rxd2 Ne3+ Kg1 Nxc4 Rc2.
Facts:
- After Ne3+, White's best reply is Bxe3.
- The roo... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 4r1k1/p4p2/7p/6p1/2R5/P4P2/1PnBr1PP/3R1K2 b - - 1 23
Black to move, move 23.
Move played: Ne3+.
Verdict: Blunder... | |
mate | MIT | true | mate_0a1631ca361ea9fc | 3r1k2/pQ4p1/2p3p1/4N2q/3rpP2/P7/1P5P/5RK1 w - - 0 34 | b7f7 | Qf7# | Displace the piece to a more promising position, strengthening its board authority. Tactical line: Qf7# Checkmate! | null | null | explain_move | beginner | short | Only move | {
"fen": "3r1k2/p4Qp1/2p3p1/4N2q/3rpP2/P7/1P5P/5RK1 b - - 1 34",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": []
}
]
} | {
"fen": "3r1k2/pQ4p1/2p3p1/4N2q/3rpP2/P7/1P5P/5RK1 w - - 0 34",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": [
"b7f7"
]
},
{
"score": {
"type": "cp",
"value": -190
},
"moves": [
"g1h1",
"f8... | [
"Black king is in check on f8.",
"Black is up a minor piece in material.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 3r1k2/pQ4p1/2p3p1/4N2q/3rpP2/P7/1P5P/5RK1 w - - 0 34
White to move, move 34.
Move played: Qf7#.
Verdict: Only move.
White's winning chances: 100% → 100%.
Best move: Qf7#.
Best line: Qf7#.
Facts:
- Black king is in check on f8.
- Black is up a minor piece in materia... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 3r1k2/pQ4p1/2p3p1/4N2q/3rpP2/P7/1P5P/5RK1 w - - 0 34
White to move, move 34.
Move played: Qf7#.
Verdict: Only mo... | |
mate | MIT | true | mate_0a3031a21c626337 | 4QR2/6pk/7p/3Pp3/1p2P1P1/3PqRK1/P7/7r b - - 4 42 | e3g1 | Qg1# | Move the piece to a pivotal position, providing it with greater board command. Tactical line: Qg1# Checkmate! | null | null | explain_move | beginner | short | Only move | {
"fen": "4QR2/6pk/7p/3Pp3/1p2P1P1/3P1RK1/P7/6qr w - - 5 43",
"pvs": [
{
"score": {
"type": "mate",
"value": -1
},
"moves": []
}
]
} | {
"fen": "4QR2/6pk/7p/3Pp3/1p2P1P1/3PqRK1/P7/7r b - - 4 42",
"pvs": [
{
"score": {
"type": "mate",
"value": -1
},
"moves": [
"e3g1"
]
},
{
"score": {
"type": "cp",
"value": 0
},
"moves": [
"e3e1",
"f3f2",
... | [
"White king is in check on g3.",
"White is up two minor pieces in material.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 4QR2/6pk/7p/3Pp3/1p2P1P1/3PqRK1/P7/7r b - - 4 42
Black to move, move 42.
Move played: Qg1#.
Verdict: Only move.
Black's winning chances: 100% → 100%.
Best move: Qg1#.
Best line: Qg1#.
Facts:
- White king is in check on g3.
- White is up two minor pieces in material... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 4QR2/6pk/7p/3Pp3/1p2P1P1/3PqRK1/P7/7r b - - 4 42
Black to move, move 42.
Move played: Qg1#.
Verdict: Only move.
... | |
mate | MIT | true | mate_0a67fd0bb3dacb33 | 2k5/p1p2p2/1pb1p3/5nB1/8/8/PPP1BP1r/2KR4 w - - 0 21 | e2a6 | Ba6+ | Reposition the piece to an assertive square, where it governs more of the board. Tactical line: Ba6+ Kb8 Rd8# Checkmate! | null | null | explain_move | beginner | short | Only move | {
"fen": "2k5/p1p2p2/Bpb1p3/5nB1/8/8/PPP2P1r/2KR4 b - - 1 21",
"pvs": [
{
"score": {
"type": "mate",
"value": 2
},
"moves": [
"c6b7",
"d1d8"
]
}
]
} | {
"fen": "2k5/p1p2p2/1pb1p3/5nB1/8/8/PPP1BP1r/2KR4 w - - 0 21",
"pvs": [
{
"score": {
"type": "mate",
"value": 2
},
"moves": [
"e2a6",
"c6b7",
"d1d8"
]
},
{
"score": {
"type": "cp",
"value": -103
},
"moves"... | [
"After Ba6+, Black's best reply is Bb7.",
"Black king is in check on c8.",
"Black is up a pawn in material.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 2k5/p1p2p2/1pb1p3/5nB1/8/8/PPP1BP1r/2KR4 w - - 0 21
White to move, move 21.
Move played: Ba6+.
Verdict: Only move.
White's winning chances: 100% → 100%.
Best move: Ba6+.
Best line: Ba6+ Bb7 Rd8#.
Facts:
- After Ba6+, Black's best reply is Bb7.
- Black king is in ch... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 2k5/p1p2p2/1pb1p3/5nB1/8/8/PPP1BP1r/2KR4 w - - 0 21
White to move, move 21.
Move played: Ba6+.
Verdict: Only mov... | |
mate | MIT | true | mate_0abbc3d8c04a0b15 | R4Q2/1ppkn3/p6p/6b1/3P2P1/1Pq5/P2r4/1K2R3 w - - 0 31 | f8e8 | Qe8+ | Place the piece in a commanding position, maximizing its control on the board. Tactical line: Qe8+ Kd6 Rd8# Checkmate! | null | null | explain_move | beginner | short | Only move | {
"fen": "R3Q3/1ppkn3/p6p/6b1/3P2P1/1Pq5/P2r4/1K2R3 b - - 1 31",
"pvs": [
{
"score": {
"type": "mate",
"value": 2
},
"moves": [
"d7d6",
"a8d8"
]
}
]
} | {
"fen": "R4Q2/1ppkn3/p6p/6b1/3P2P1/1Pq5/P2r4/1K2R3 w - - 0 31",
"pvs": [
{
"score": {
"type": "mate",
"value": 2
},
"moves": [
"f8e8",
"d7d6",
"a8d8"
]
},
{
"score": {
"type": "cp",
"value": -305
},
"moves... | [
"After Qe8+, Black's best reply is Kd6.",
"Black king is in check on d7.",
"Black is up a pawn in material.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: R4Q2/1ppkn3/p6p/6b1/3P2P1/1Pq5/P2r4/1K2R3 w - - 0 31
White to move, move 31.
Move played: Qe8+.
Verdict: Only move.
White's winning chances: 100% → 100%.
Best move: Qe8+.
Best line: Qe8+ Kd6 Rd8#.
Facts:
- After Qe8+, Black's best reply is Kd6.
- Black king is in c... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: R4Q2/1ppkn3/p6p/6b1/3P2P1/1Pq5/P2r4/1K2R3 w - - 0 31
White to move, move 31.
Move played: Qe8+.
Verdict: Only mo... | |
mate | MIT | true | mate_0ae0096038f0f2ea | r1b2rk1/ppNn1pbp/3p1np1/4q2P/5B2/3BP3/PPP3P1/R2QK1NR b KQ - 2 12 | a8b8 | Rb8 | Move the piece to a pivotal position, providing it with greater board command. Tactical line: Rb8 Bxe5 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Blunder | {
"fen": "1rb2rk1/ppNn1pbp/3p1np1/4q2P/5B2/3BP3/PPP3P1/R2QK1NR w KQ - 3 13",
"pvs": [
{
"score": {
"type": "cp",
"value": 774
},
"moves": [
"f4e5",
"d7e5",
"d3e2",
"c8g4",
"c7b5",
"g4e2",
"d1e2"
]
}
]
} | {
"fen": "r1b2rk1/ppNn1pbp/3p1np1/4q2P/5B2/3BP3/PPP3P1/R2QK1NR b KQ - 2 12",
"pvs": [
{
"score": {
"type": "cp",
"value": -566
},
"moves": [
"e5a5",
"c2c3",
"a5c7",
"d3g6",
"d7e5",
"f4e5",
"d6e5",
"h5h6",
"... | [
"After Rb8, White's best reply is Bxe5.",
"White can capture the queen on e5 with Bxe5.",
"Black threatens Qa5+.",
"White has not castled.",
"Material: equal.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: r1b2rk1/ppNn1pbp/3p1np1/4q2P/5B2/3BP3/PPP3P1/R2QK1NR b KQ - 2 12
Black to move, move 12.
Move played: Rb8.
Verdict: Blunder.
Black's winning chances: 89% → 5%.
Best move: Qa5+.
Best line: Qa5+ c3 Qxc7 Bxg6 Ne5 Bxe5.
Facts:
- After Rb8, White's best reply is Bxe5.
-... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: r1b2rk1/ppNn1pbp/3p1np1/4q2P/5B2/3BP3/PPP3P1/R2QK1NR b KQ - 2 12
Black to move, move 12.
Move played: Rb8.
Verdi... | |
mate | MIT | true | mate_0b1fd0a595c0714d | r1bq1rk1/ppp2pb1/2n3pQ/3p2N1/3P3P/2PBP3/PP3PP1/R3K2R w KQ - 3 16 | h6h7 | Qh7# | Redeploy the piece to a vibrant location, increasing its board dominance. Tactical line: Qh7# Checkmate! | null | null | explain_move | beginner | short | Only move | {
"fen": "r1bq1rk1/ppp2pbQ/2n3p1/3p2N1/3P3P/2PBP3/PP3PP1/R3K2R b KQ - 4 16",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": []
}
]
} | {
"fen": "r1bq1rk1/ppp2pb1/2n3pQ/3p2N1/3P3P/2PBP3/PP3PP1/R3K2R w KQ - 3 16",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": [
"h6h7"
]
},
{
"score": {
"type": "cp",
"value": -769
},
"moves": [
"g5f7",... | [
"White has not castled.",
"Black king is in check on g8.",
"Black is up a pawn in material.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: r1bq1rk1/ppp2pb1/2n3pQ/3p2N1/3P3P/2PBP3/PP3PP1/R3K2R w KQ - 3 16
White to move, move 16.
Move played: Qh7#.
Verdict: Only move.
White's winning chances: 100% → 100%.
Best move: Qh7#.
Best line: Qh7#.
Facts:
- White has not castled.
- Black king is in check on g8.
-... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: r1bq1rk1/ppp2pb1/2n3pQ/3p2N1/3P3P/2PBP3/PP3PP1/R3K2R w KQ - 3 16
White to move, move 16.
Move played: Qh7#.
Verd... | |
mate | MIT | true | mate_0b2514554559428f | 6k1/p4p1p/2pQ1bpB/2Pp4/7q/7P/P4PPK/8 w - - 2 26 | d6f8 | Qf8# | Position the piece more actively, giving it greater board command. Tactical line: Qf8# Checkmate! | null | null | explain_move | beginner | short | Only move | {
"fen": "5Qk1/p4p1p/2p2bpB/2Pp4/7q/7P/P4PPK/8 b - - 3 26",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": []
}
]
} | {
"fen": "6k1/p4p1p/2pQ1bpB/2Pp4/7q/7P/P4PPK/8 w - - 2 26",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": [
"d6f8"
]
},
{
"score": {
"type": "cp",
"value": 42
},
"moves": [
"d6b8",
"f6d8",
... | [
"Black king is in check on g8.",
"Black is up a pawn.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 6k1/p4p1p/2pQ1bpB/2Pp4/7q/7P/P4PPK/8 w - - 2 26
White to move, move 26.
Move played: Qf8#.
Verdict: Only move.
White's winning chances: 100% → 100%.
Best move: Qf8#.
Best line: Qf8#.
Facts:
- Black king is in check on g8.
- Black is up a pawn.
- Phase: endgame. | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 6k1/p4p1p/2pQ1bpB/2Pp4/7q/7P/P4PPK/8 w - - 2 26
White to move, move 26.
Move played: Qf8#.
Verdict: Only move.
W... | |
mate | MIT | true | mate_0b64fdb10bdc5168 | r1b1r1k1/ppq2pbp/2p2np1/2p5/3BP3/2N2Q2/PP3PPP/2R1RBK1 w - - 0 15 | c3b5 | Nb5 | Move the piece to a stronger position, enhancing its board control. Tactical line: Nb5 Qd8 e5 cxd4 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Blunder | {
"fen": "r1b1r1k1/ppq2pbp/2p2np1/1Np5/3BP3/5Q2/PP3PPP/2R1RBK1 b - - 1 15",
"pvs": [
{
"score": {
"type": "cp",
"value": -139
},
"moves": [
"c6b5",
"d4f6",
"g7f6",
"f3f6",
"a7a6",
"h2h4",
"h7h5",
"b2b3",
"c... | {
"fen": "r1b1r1k1/ppq2pbp/2p2np1/2p5/3BP3/2N2Q2/PP3PPP/2R1RBK1 w - - 0 15",
"pvs": [
{
"score": {
"type": "cp",
"value": 631
},
"moves": [
"d4f6",
"c8g4",
"f3g4",
"g7f6",
"g2g3",
"c7e5",
"g4f3",
"h7h5",
"a... | [
"Nb5 attacks the queen on c7.",
"After Nb5, Black's best reply is cxb5.",
"After Nb5, Black captures the knight on b5 with cxb5.",
"The queen on c7 is not defended.",
"Black has a check: Qxh2+.",
"Black can capture the bishop on d4 with cxd4.",
"White threatens Nxc7.",
"Black is up a pawn.",
"Phase:... | task: explain_move
level: beginner
detail: short
FEN: r1b1r1k1/ppq2pbp/2p2np1/2p5/3BP3/2N2Q2/PP3PPP/2R1RBK1 w - - 0 15
White to move, move 15.
Move played: Nb5.
Verdict: Blunder.
White's winning chances: 91% → 37%.
Best move: Bxf6.
Best line: Bxf6 Bg4 Qxg4 Bxf6 g3 Qe5.
Facts:
- Nb5 attacks the queen on c7.
- After Nb5... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: r1b1r1k1/ppq2pbp/2p2np1/2p5/3BP3/2N2Q2/PP3PPP/2R1RBK1 w - - 0 15
White to move, move 15.
Move played: Nb5.
Verdi... | |
mate | MIT | true | mate_0bdf21480027c4f1 | r1b1kr2/p1p2Npp/2p5/4p3/8/2P1P1P1/PPP4q/R2QKR2 w Qq - 0 14 | d1d8 | Qd8# | Transfer the piece to a lively area, boosting its impact on the board. Tactical line: Qd8# Checkmate! | null | null | explain_move | beginner | short | Only move | {
"fen": "r1bQkr2/p1p2Npp/2p5/4p3/8/2P1P1P1/PPP4q/R3KR2 b Qq - 1 14",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": []
}
]
} | {
"fen": "r1b1kr2/p1p2Npp/2p5/4p3/8/2P1P1P1/PPP4q/R2QKR2 w Qq - 0 14",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": [
"d1d8"
]
},
{
"score": {
"type": "cp",
"value": 250
},
"moves": [
"d1f3",
... | [
"White has not castled.",
"Black king is in check on e8.",
"Material: equal.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: r1b1kr2/p1p2Npp/2p5/4p3/8/2P1P1P1/PPP4q/R2QKR2 w Qq - 0 14
White to move, move 14.
Move played: Qd8#.
Verdict: Only move.
White's winning chances: 100% → 100%.
Best move: Qd8#.
Best line: Qd8#.
Facts:
- White has not castled.
- Black king is in check on e8.
- Mater... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: r1b1kr2/p1p2Npp/2p5/4p3/8/2P1P1P1/PPP4q/R2QKR2 w Qq - 0 14
White to move, move 14.
Move played: Qd8#.
Verdict: O... | |
mate | MIT | true | mate_0c04d0020ab730af | 3N3k/5p1p/p3b1p1/1pQ1b3/6P1/P1P4q/1KP5/8 w - - 0 37 | c5f8 | Qf8# | Marshall the piece to a better square, extending its control over the board. Tactical line: Qf8# Checkmate! | null | null | explain_move | beginner | short | Only move | {
"fen": "3N1Q1k/5p1p/p3b1p1/1p2b3/6P1/P1P4q/1KP5/8 b - - 1 37",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": []
}
]
} | {
"fen": "3N3k/5p1p/p3b1p1/1pQ1b3/6P1/P1P4q/1KP5/8 w - - 0 37",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": [
"c5f8"
]
},
{
"score": {
"type": "cp",
"value": 89
},
"moves": [
"c5e5",
"h8g8"... | [
"Black king is in check on h8.",
"Black is up a minor piece and a pawn in material.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 3N3k/5p1p/p3b1p1/1pQ1b3/6P1/P1P4q/1KP5/8 w - - 0 37
White to move, move 37.
Move played: Qf8#.
Verdict: Only move.
White's winning chances: 100% → 100%.
Best move: Qf8#.
Best line: Qf8#.
Facts:
- Black king is in check on h8.
- Black is up a minor piece and a pawn ... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 3N3k/5p1p/p3b1p1/1pQ1b3/6P1/P1P4q/1KP5/8 w - - 0 37
White to move, move 37.
Move played: Qf8#.
Verdict: Only mov... | |
mate | MIT | true | mate_0c070b3ccbb0d5e9 | r1bq1rk1/pp1p1ppp/2np4/8/3P4/2PQ1N2/PPB3PP/RN3nK1 w - - 0 14 | d3h7 | Qxh7# | Surrender a piece to establish an open file or diagonal near the rival king Tactical line: Qxh7# Checkmate! | null | null | explain_move | club | short | Only move | {
"fen": "r1bq1rk1/pp1p1ppQ/2np4/8/3P4/2P2N2/PPB3PP/RN3nK1 b - - 0 14",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": []
}
]
} | {
"fen": "r1bq1rk1/pp1p1ppp/2np4/8/3P4/2PQ1N2/PPB3PP/RN3nK1 w - - 0 14",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": [
"d3h7"
]
},
{
"score": {
"type": "cp",
"value": -222
},
"moves": [
"b1a3",
... | [
"The knight on f1 is not defended.",
"Black king is in check on g8.",
"Black is up two minor pieces in material.",
"Phase: middlegame."
] | task: explain_move
level: club
detail: short
FEN: r1bq1rk1/pp1p1ppp/2np4/8/3P4/2PQ1N2/PPB3PP/RN3nK1 w - - 0 14
White to move, move 14.
Move played: Qxh7#.
Verdict: Only move.
White's winning chances: 100% → 100%.
Best move: Qxh7#.
Best line: Qxh7#.
Facts:
- The knight on f1 is not defended.
- Black king is in check on... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: club
detail: short
FEN: r1bq1rk1/pp1p1ppp/2np4/8/3P4/2PQ1N2/PPB3PP/RN3nK1 w - - 0 14
White to move, move 14.
Move played: Qxh7#.
Verdict: On... | |
mate | MIT | true | mate_0c5afd62f84af5ac | 4rrk1/1p3ppp/p1pp4/4P3/8/2qBQ1Pb/P6P/R3R2K w - - 1 22 | d3h7 | Bxh7+ | Offer a piece to clear a file or diagonal close to the enemy king Tactical line: Bxh7+ Kxh7 Trade the lower value piece for a higher value piece. | null | null | explain_move | club | short | Only move | {
"fen": "4rrk1/1p3ppB/p1pp4/4P3/8/2q1Q1Pb/P6P/R3R2K b - - 0 22",
"pvs": [
{
"score": {
"type": "cp",
"value": 645
},
"moves": [
"g8h7",
"e3c3",
"h7g8",
"e1e3",
"h3d7",
"h1g1",
"e8e5",
"a1e1"
]
}
]
} | {
"fen": "4rrk1/1p3ppp/p1pp4/4P3/8/2qBQ1Pb/P6P/R3R2K w - - 1 22",
"pvs": [
{
"score": {
"type": "cp",
"value": 645
},
"moves": [
"d3h7",
"g8h7",
"e3c3",
"h7g8",
"e1e3",
"h3d7",
"h1g1",
"e8e5",
"a1e1"
... | [
"After Bxh7+, Black's best reply is Kxh7.",
"The queen on c3 is not defended.",
"The bishop on h7 is not defended.",
"Black can capture the bishop on h7 with Kxh7.",
"Black king is in check on g8.",
"Black is up a minor piece in material.",
"Phase: middlegame."
] | task: explain_move
level: club
detail: short
FEN: 4rrk1/1p3ppp/p1pp4/4P3/8/2qBQ1Pb/P6P/R3R2K w - - 1 22
White to move, move 22.
Move played: Bxh7+.
Verdict: Only move.
White's winning chances: 91% → 91%.
Best move: Bxh7+.
Best line: Bxh7+ Kxh7 Qxc3 Kg8 Re3 Bd7.
Facts:
- After Bxh7+, Black's best reply is Kxh7.
- The q... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: club
detail: short
FEN: 4rrk1/1p3ppp/p1pp4/4P3/8/2qBQ1Pb/P6P/R3R2K w - - 1 22
White to move, move 22.
Move played: Bxh7+.
Verdict: Only move... | |
mate | MIT | true | mate_0c5b918c519ba2b3 | 5r2/1p1qp1k1/3p2p1/2pP1bB1/5QP1/8/1nP5/5RK1 w - - 3 40 | g5h6 | Bh6+ | Advance the piece to a strategic square, optimizing its control over the board. Tactical line: Bh6+ Kf7 gxf5 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Only move | {
"fen": "5r2/1p1qp1k1/3p2pB/2pP1b2/5QP1/8/1nP5/5RK1 b - - 4 40",
"pvs": [
{
"score": {
"type": "cp",
"value": 341
},
"moves": [
"g7g8",
"h6f8",
"d7a4",
"f8e7",
"a4f4",
"f1f4",
"f5c2",
"e7d6",
"b2a4",
... | {
"fen": "5r2/1p1qp1k1/3p2p1/2pP1bB1/5QP1/8/1nP5/5RK1 w - - 3 40",
"pvs": [
{
"score": {
"type": "cp",
"value": 341
},
"moves": [
"g5h6",
"g7g8",
"h6f8",
"d7a4",
"f8e7",
"a4f4",
"f1f4",
"f5c2",
"e7d6",
... | [
"After Bh6+, Black's best reply is Kg8.",
"Black king is in check on g7.",
"Black is up a rook in material.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: 5r2/1p1qp1k1/3p2p1/2pP1bB1/5QP1/8/1nP5/5RK1 w - - 3 40
White to move, move 40.
Move played: Bh6+.
Verdict: Only move.
White's winning chances: 78% → 78%.
Best move: Bh6+.
Best line: Bh6+ Kg8 Bxf8 Qa4 Bxe7 Qxf4.
Facts:
- After Bh6+, Black's best reply is Kg8.
- Blac... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 5r2/1p1qp1k1/3p2p1/2pP1bB1/5QP1/8/1nP5/5RK1 w - - 3 40
White to move, move 40.
Move played: Bh6+.
Verdict: Only ... | |
mate | MIT | true | mate_0c704a3937640661 | 5r2/p1p4k/1pPpr1pp/8/4q3/1Q4R1/P4PP1/5RK1 w - - 3 35 | g3e3 | Re3 | Transfer the piece to a lively area, boosting its impact on the board. Tactical line: Re3 Rf4 Rxe4 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Only move | {
"fen": "5r2/p1p4k/1pPpr1pp/8/4q3/1Q2R3/P4PP1/5RK1 b - - 4 35",
"pvs": [
{
"score": {
"type": "cp",
"value": 517
},
"moves": [
"e4e3",
"f2e3",
"f8f1",
"g1f1",
"e6f6",
"f1g1",
"f6f5",
"e3e4",
"f5a5",
... | {
"fen": "5r2/p1p4k/1pPpr1pp/8/4q3/1Q4R1/P4PP1/5RK1 w - - 3 35",
"pvs": [
{
"score": {
"type": "cp",
"value": 517
},
"moves": [
"g3e3",
"e4e3",
"f2e3",
"f8f1",
"g1f1",
"e6f6",
"f1g1",
"f6f5",
"e3e4",
... | [
"Re3 attacks the queen on e4.",
"After Re3, Black's best reply is Qxe3.",
"Black has a check: Qxg2+.",
"Black can capture the rook on e3 with Qxe3.",
"White threatens Rxe4.",
"Black is up two pawns.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 5r2/p1p4k/1pPpr1pp/8/4q3/1Q4R1/P4PP1/5RK1 w - - 3 35
White to move, move 35.
Move played: Re3.
Verdict: Only move.
White's winning chances: 87% → 87%.
Best move: Re3.
Best line: Re3 Qxe3 fxe3 Rxf1+ Kxf1 Rf6+.
Facts:
- Re3 attacks the queen on e4.
- After Re3, Black... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 5r2/p1p4k/1pPpr1pp/8/4q3/1Q4R1/P4PP1/5RK1 w - - 3 35
White to move, move 35.
Move played: Re3.
Verdict: Only mov... | |
mate | MIT | true | mate_0cac4e996142f38d | 2r2r1k/p1NR3p/5pp1/2Q5/6q1/8/1PP5/1K6 w - - 0 31 | c5e7 | Qe7 | Move the piece to an aggressive spot, enhancing its control over the board. Tactical line: Qe7 Qxd7 Qxd7 Rg8 c4 Rxc7 | null | null | explain_move | beginner | short | Only move | {
"fen": "2r2r1k/p1NRQ2p/5pp1/8/6q1/8/1PP5/1K6 b - - 1 31",
"pvs": [
{
"score": {
"type": "cp",
"value": 523
},
"moves": [
"g4d7",
"e7d7",
"c8c7",
"d7c7",
"g6g5",
"c7d6",
"h8g7",
"d6d7",
"f8f7",
"d7... | {
"fen": "2r2r1k/p1NR3p/5pp1/2Q5/6q1/8/1PP5/1K6 w - - 0 31",
"pvs": [
{
"score": {
"type": "cp",
"value": 523
},
"moves": [
"c5e7",
"g4d7",
"e7d7",
"c8c7",
"d7c7",
"g6g5",
"c7d6",
"h8g7",
"d6d7",
"f... | [
"Qe7 attacks the rook on f8.",
"After Qe7, Black's best reply is Qxd7.",
"Black has a check: Qd1+.",
"Black can capture the rook on d7 with Qxd7.",
"White threatens Qg7#.",
"Black is up a minor piece and a pawn in material.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 2r2r1k/p1NR3p/5pp1/2Q5/6q1/8/1PP5/1K6 w - - 0 31
White to move, move 31.
Move played: Qe7.
Verdict: Only move.
White's winning chances: 87% → 87%.
Best move: Qe7.
Best line: Qe7 Qxd7 Qxd7 Rxc7 Qxc7 g5.
Facts:
- Qe7 attacks the rook on f8.
- After Qe7, Black's best ... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 2r2r1k/p1NR3p/5pp1/2Q5/6q1/8/1PP5/1K6 w - - 0 31
White to move, move 31.
Move played: Qe7.
Verdict: Only move.
W... | |
mate | MIT | true | mate_0ce91fc55f08e8a6 | r1bq1k1r/1p3Pb1/p2p2p1/2p5/P3PNn1/1B1P4/1PP3PP/R2Q1RK1 w - - 6 18 | h2h3 | h3 | A forward move by a white pawn opens up the kingside, resulting in greater freedom to reposition pieces. Tactical line: h3 Rh6 Qd2 g5 Ne2 Ne5 | null | null | explain_move | beginner | short | Blunder | {
"fen": "r1bq1k1r/1p3Pb1/p2p2p1/2p5/P3PNn1/1B1P3P/1PP3P1/R2Q1RK1 b - - 0 18",
"pvs": [
{
"score": {
"type": "cp",
"value": -151
},
"moves": [
"g7d4",
"g1h1",
"d8g5",
"d1e2",
"d4e5",
"e2d2",
"e5f4",
"f1f4",
... | {
"fen": "r1bq1k1r/1p3Pb1/p2p2p1/2p5/P3PNn1/1B1P4/1PP3PP/R2Q1RK1 w - - 6 18",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": [
"f4g6"
]
},
{
"score": {
"type": "cp",
"value": -110
},
"moves": [
"e4e5"... | [
"h3 attacks the knight on g4 together with the queen on d1.",
"After h3, Black's best reply is Bd4+.",
"Black has a check: Bd4+.",
"White threatens Nxg6#.",
"Material: equal.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: r1bq1k1r/1p3Pb1/p2p2p1/2p5/P3PNn1/1B1P4/1PP3PP/R2Q1RK1 w - - 6 18
White to move, move 18.
Move played: h3.
Verdict: Blunder.
White's winning chances: 100% → 36%.
Best move: Nxg6#.
Best line: Nxg6#.
Facts:
- h3 attacks the knight on g4 together with the queen on d1.... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: r1bq1k1r/1p3Pb1/p2p2p1/2p5/P3PNn1/1B1P4/1PP3PP/R2Q1RK1 w - - 6 18
White to move, move 18.
Move played: h3.
Verdi... | |
mate | MIT | true | mate_0d0ed546c5ec4068 | r3k2r/1b3ppp/p3p3/1p1q4/3N4/1P1B4/P1PQ1PPP/R3R1K1 b kq - 0 15 | d5g2 | Qxg2# | Lose a piece to create an opening on a file or diagonal near the rival king Tactical line: Qxg2# Checkmate! | null | null | explain_move | club | short | Only move | {
"fen": "r3k2r/1b3ppp/p3p3/1p6/3N4/1P1B4/P1PQ1PqP/R3R1K1 w kq - 0 16",
"pvs": [
{
"score": {
"type": "mate",
"value": -1
},
"moves": []
}
]
} | {
"fen": "r3k2r/1b3ppp/p3p3/1p1q4/3N4/1P1B4/P1PQ1PPP/R3R1K1 b kq - 0 15",
"pvs": [
{
"score": {
"type": "mate",
"value": -1
},
"moves": [
"d5g2"
]
},
{
"score": {
"type": "cp",
"value": 639
},
"moves": [
"e8g8",
... | [
"White king is in check on g1.",
"Black has not castled.",
"White is up a knight.",
"Phase: middlegame."
] | task: explain_move
level: club
detail: short
FEN: r3k2r/1b3ppp/p3p3/1p1q4/3N4/1P1B4/P1PQ1PPP/R3R1K1 b kq - 0 15
Black to move, move 15.
Move played: Qxg2#.
Verdict: Only move.
Black's winning chances: 100% → 100%.
Best move: Qxg2#.
Best line: Qxg2#.
Facts:
- White king is in check on g1.
- Black has not castled.
- Whi... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: club
detail: short
FEN: r3k2r/1b3ppp/p3p3/1p1q4/3N4/1P1B4/P1PQ1PPP/R3R1K1 b kq - 0 15
Black to move, move 15.
Move played: Qxg2#.
Verdict: O... | |
mate | MIT | true | mate_0d168b4c3cc8c1c2 | 8/p7/1p5p/1Pp1kp2/2P3P1/P4K1P/8/8 b - - 1 44 | f5g4 | fxg4+ | A capture by the pawn changes the pawn lineup. Tactical line: fxg4+ Kxg4 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Only move | {
"fen": "8/p7/1p5p/1Pp1k3/2P3p1/P4K1P/8/8 w - - 0 45",
"pvs": [
{
"score": {
"type": "cp",
"value": -519
},
"moves": [
"h3g4",
"e5d4",
"a3a4",
"d4c4",
"f3e4",
"c4b3",
"a4a5",
"c5c4",
"a5b6",
"a7b6"... | {
"fen": "8/p7/1p5p/1Pp1kp2/2P3P1/P4K1P/8/8 b - - 1 44",
"pvs": [
{
"score": {
"type": "cp",
"value": -519
},
"moves": [
"f5g4",
"h3g4",
"e5d4",
"a3a4",
"d4c4",
"f3e4",
"c4b3",
"a4a5",
"c5c4",
"a5b6... | [
"After fxg4+, White's best reply is hxg4.",
"After fxg4+, White captures the pawn on g4 with hxg4.",
"White king is in check on f3.",
"Material: equal.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 8/p7/1p5p/1Pp1kp2/2P3P1/P4K1P/8/8 b - - 1 44
Black to move, move 44.
Move played: fxg4+.
Verdict: Only move.
Black's winning chances: 87% → 87%.
Best move: fxg4+.
Best line: fxg4+ hxg4 Kd4 a4 Kxc4 Ke4.
Facts:
- After fxg4+, White's best reply is hxg4.
- After fxg4+... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 8/p7/1p5p/1Pp1kp2/2P3P1/P4K1P/8/8 b - - 1 44
Black to move, move 44.
Move played: fxg4+.
Verdict: Only move.
Bla... | |
mate | MIT | true | mate_0d3ff1fd1b82935c | 5k2/4bp1p/p3pNp1/6B1/1q1P4/7P/5PP1/4R1K1 w - - 8 30 | g5h6 | Bh6# | Reposition the piece to an assertive square, where it governs more of the board. Tactical line: Bh6# Checkmate! | null | null | explain_move | beginner | short | Only move | {
"fen": "5k2/4bp1p/p3pNpB/8/1q1P4/7P/5PP1/4R1K1 b - - 9 30",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": []
}
]
} | {
"fen": "5k2/4bp1p/p3pNp1/6B1/1q1P4/7P/5PP1/4R1K1 w - - 8 30",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": [
"g5h6"
]
},
{
"score": {
"type": "cp",
"value": -182
},
"moves": [
"e1c1",
"f8g... | [
"The rook on e1 is not defended.",
"The knight on f6 is not defended.",
"Black king is in check on f8.",
"Black is up two pawns in material.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 5k2/4bp1p/p3pNp1/6B1/1q1P4/7P/5PP1/4R1K1 w - - 8 30
White to move, move 30.
Move played: Bh6#.
Verdict: Only move.
White's winning chances: 100% → 100%.
Best move: Bh6#.
Best line: Bh6#.
Facts:
- The rook on e1 is not defended.
- The knight on f6 is not defended.
-... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 5k2/4bp1p/p3pNp1/6B1/1q1P4/7P/5PP1/4R1K1 w - - 8 30
White to move, move 30.
Move played: Bh6#.
Verdict: Only mov... | |
mate | MIT | true | mate_0e2eda4832fb7c00 | r4rk1/p4pp1/3bb2p/6R1/B7/3q1P2/3B1P1P/3QR1K1 w - - 0 23 | g5g7 | Rxg7+ | Remove a piece to free up a file or diagonal close to the enemy king Tactical line: Rxg7+ Kxg7 Trade the lower value piece for a higher value piece. | null | null | explain_move | club | short | Only move | {
"fen": "r4rk1/p4pR1/3bb2p/8/B7/3q1P2/3B1P1P/3QR1K1 b - - 0 23",
"pvs": [
{
"score": {
"type": "cp",
"value": 451
},
"moves": [
"g8h8",
"a4c2",
"d3d5",
"g7h7",
"h8g8",
"h7h6",
"f8d8",
"c2e4",
"d5d4",
... | {
"fen": "r4rk1/p4pp1/3bb2p/6R1/B7/3q1P2/3B1P1P/3QR1K1 w - - 0 23",
"pvs": [
{
"score": {
"type": "cp",
"value": 451
},
"moves": [
"g5g7",
"g8h8",
"a4c2",
"d3d5",
"g7h7",
"h8g8",
"h7h6",
"f8d8",
"c2e4",
... | [
"After Rxg7+, Black's best reply is Kh8.",
"The rook on g7 is not defended.",
"Black can capture the rook on g7 with Kxg7.",
"Black king is in check on g8.",
"Black is up a pawn.",
"Phase: middlegame."
] | task: explain_move
level: club
detail: short
FEN: r4rk1/p4pp1/3bb2p/6R1/B7/3q1P2/3B1P1P/3QR1K1 w - - 0 23
White to move, move 23.
Move played: Rxg7+.
Verdict: Only move.
White's winning chances: 84% → 84%.
Best move: Rxg7+.
Best line: Rxg7+ Kh8 Bc2 Qd5 Rh7+ Kg8.
Facts:
- After Rxg7+, Black's best reply is Kh8.
- The r... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: club
detail: short
FEN: r4rk1/p4pp1/3bb2p/6R1/B7/3q1P2/3B1P1P/3QR1K1 w - - 0 23
White to move, move 23.
Move played: Rxg7+.
Verdict: Only mo... | |
mate | MIT | true | mate_0e39f9aa1e85c077 | 8/6pp/p1b5/1p3N2/1P2pP2/Pk2K1P1/7P/8 w - - 1 39 | f5d4 | Nd4+ | Move the piece to a pivotal position, providing it with greater board command. Tactical line: Nd4+ Kxa3 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Only move | {
"fen": "8/6pp/p1b5/1p6/1P1NpP2/Pk2K1P1/7P/8 b - - 2 39",
"pvs": [
{
"score": {
"type": "cp",
"value": 513
},
"moves": [
"b3a3",
"d4c6",
"h7h5",
"e3e4",
"h5h4",
"e4d5",
"a6a5",
"b4a5",
"b5b4",
"a5a... | {
"fen": "8/6pp/p1b5/1p3N2/1P2pP2/Pk2K1P1/7P/8 w - - 1 39",
"pvs": [
{
"score": {
"type": "cp",
"value": 513
},
"moves": [
"f5d4",
"b3a3",
"d4c6",
"h7h5",
"e3e4",
"h5h4",
"e4d5",
"a6a5",
"b4a5",
"b5... | [
"After Nd4+, Black's best reply is Kxa3.",
"The bishop on c6 is not defended.",
"Black king is in check on b3.",
"Material: equal.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 8/6pp/p1b5/1p3N2/1P2pP2/Pk2K1P1/7P/8 w - - 1 39
White to move, move 39.
Move played: Nd4+.
Verdict: Only move.
White's winning chances: 87% → 87%.
Best move: Nd4+.
Best line: Nd4+ Kxa3 Nxc6 h5 Kxe4 h4.
Facts:
- After Nd4+, Black's best reply is Kxa3.
- The bishop o... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 8/6pp/p1b5/1p3N2/1P2pP2/Pk2K1P1/7P/8 w - - 1 39
White to move, move 39.
Move played: Nd4+.
Verdict: Only move.
W... | |
mate | MIT | true | mate_0e7ac54cfcd58798 | r1b2rk1/pp1q1p1p/3p2P1/2pB2P1/4PB2/2P2n2/P3NP2/R2Q1K1R b - - 0 19 | d7h3 | Qh3+ | Shift the piece to a proactive position, where it exerts more influence. Tactical line: Qh3+ Rxh3 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Only move | {
"fen": "r1b2rk1/pp3p1p/3p2P1/2pB2P1/4PB2/2P2n1q/P3NP2/R2Q1K1R w - - 1 20",
"pvs": [
{
"score": {
"type": "mate",
"value": -2
},
"moves": [
"h1h3",
"c8h3"
]
}
]
} | {
"fen": "r1b2rk1/pp1q1p1p/3p2P1/2pB2P1/4PB2/2P2n2/P3NP2/R2Q1K1R b - - 0 19",
"pvs": [
{
"score": {
"type": "mate",
"value": -2
},
"moves": [
"d7h3",
"h1h3",
"c8h3"
]
},
{
"score": {
"type": "cp",
"value": 614
},... | [
"After Qh3+, White's best reply is Rxh3.",
"The rook on h1 is not defended.",
"White can capture the queen on h3 with Rxh3.",
"White king is in check on f1.",
"White is up a bishop.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: r1b2rk1/pp1q1p1p/3p2P1/2pB2P1/4PB2/2P2n2/P3NP2/R2Q1K1R b - - 0 19
Black to move, move 19.
Move played: Qh3+.
Verdict: Only move.
Black's winning chances: 100% → 100%.
Best move: Qh3+.
Best line: Qh3+ Rxh3 Bxh3#.
Facts:
- After Qh3+, White's best reply is Rxh3.
- Th... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: r1b2rk1/pp1q1p1p/3p2P1/2pB2P1/4PB2/2P2n2/P3NP2/R2Q1K1R b - - 0 19
Black to move, move 19.
Move played: Qh3+.
Ver... | |
mate | MIT | true | mate_0e83d2edf9890ec9 | 6k1/p4pp1/7p/3Q4/5P2/2P1KPr1/P5b1/8 b - - 0 31 | g3f3 | Rxf3+ | Sacrifice a piece to open a channel or diagonal near the opponent's king Tactical line: Rxf3+ Qxf3 Bxf3 Trade the lower value piece for a higher value piece. | null | null | explain_move | club | short | Only move | {
"fen": "6k1/p4pp1/7p/3Q4/5P2/2P1Kr2/P5b1/8 w - - 0 32",
"pvs": [
{
"score": {
"type": "cp",
"value": -449
},
"moves": [
"d5f3",
"g2f3",
"e3f3",
"g8f8",
"c3c4",
"f8e7",
"c4c5",
"g7g6",
"f4f5",
"g6f... | {
"fen": "6k1/p4pp1/7p/3Q4/5P2/2P1KPr1/P5b1/8 b - - 0 31",
"pvs": [
{
"score": {
"type": "cp",
"value": -449
},
"moves": [
"g3f3",
"d5f3",
"g2f3",
"e3f3",
"g8f8",
"c3c4",
"f8e7",
"c4c5",
"g7g6",
"f4... | [
"After Rxf3+, White's best reply is Qxf3.",
"White can capture the rook on f3 with Qxf3.",
"White king is in check on e3.",
"White is up a pawn in material.",
"Phase: endgame."
] | task: explain_move
level: club
detail: short
FEN: 6k1/p4pp1/7p/3Q4/5P2/2P1KPr1/P5b1/8 b - - 0 31
Black to move, move 31.
Move played: Rxf3+.
Verdict: Only move.
Black's winning chances: 84% → 84%.
Best move: Rxf3+.
Best line: Rxf3+ Qxf3 Bxf3 Kxf3 Kf8 c4.
Facts:
- After Rxf3+, White's best reply is Qxf3.
- White can ca... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: club
detail: short
FEN: 6k1/p4pp1/7p/3Q4/5P2/2P1KPr1/P5b1/8 b - - 0 31
Black to move, move 31.
Move played: Rxf3+.
Verdict: Only move.
Black... | |
mate | MIT | true | mate_0ed60bf8417fcd0f | 1r4k1/2p2pp1/p6p/2p1qN2/2P1Pn2/3Q1P2/P2R2PP/1r1R2K1 w - - 9 30 | d3d7 | Qd7 | Plant the piece in a dominant spot, expanding its control over the board. Tactical line: Qd7 Qa1 h3 Ne2+ Kf2 Nd4 | null | null | explain_move | beginner | short | Blunder | {
"fen": "1r4k1/2pQ1pp1/p6p/2p1qN2/2P1Pn2/5P2/P2R2PP/1r1R2K1 b - - 10 30",
"pvs": [
{
"score": {
"type": "cp",
"value": -101
},
"moves": [
"g8h7",
"g2g3",
"f4e6",
"d7f7",
"e5c3",
"g1g2"
]
}
]
} | {
"fen": "1r4k1/2p2pp1/p6p/2p1qN2/2P1Pn2/3Q1P2/P2R2PP/1r1R2K1 w - - 9 30",
"pvs": [
{
"score": {
"type": "cp",
"value": 390
},
"moves": [
"d1b1",
"f4d3",
"b1b8",
"g8h7",
"d2d3",
"e5a1",
"g1f2",
"a1a2",
"f2g... | [
"After Qd7, Black's best reply is Kh7.",
"Black has a check: Rxd1+.",
"Black can capture the knight on f5 with Qxf5.",
"White threatens Ne7+.",
"Material: equal.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: 1r4k1/2p2pp1/p6p/2p1qN2/2P1Pn2/3Q1P2/P2R2PP/1r1R2K1 w - - 9 30
White to move, move 30.
Move played: Qd7.
Verdict: Blunder.
White's winning chances: 81% → 41%.
Best move: Rxb1.
Best line: Rxb1 Nxd3 Rxb8+ Kh7 Rxd3 Qa1+.
Facts:
- After Qd7, Black's best reply is Kh7.
... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 1r4k1/2p2pp1/p6p/2p1qN2/2P1Pn2/3Q1P2/P2R2PP/1r1R2K1 w - - 9 30
White to move, move 30.
Move played: Qd7.
Verdict... | |
mate | MIT | true | mate_0f12481890e82c39 | r2qk2r/pp2npp1/2n1b2p/b1Bp4/2B5/PQ3N2/1PP2PPP/RN1R2K1 b kq - 3 14 | d5c4 | dxc4 | Replace the lower-value piece with a more valuable one to secure an advantage. Tactical line: dxc4 Nbd2 cxb3 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Only move | {
"fen": "r2qk2r/pp2npp1/2n1b2p/b1B5/2p5/PQ3N2/1PP2PPP/RN1R2K1 w kq - 0 15",
"pvs": [
{
"score": {
"type": "cp",
"value": -806
},
"moves": [
"d1d8",
"a8d8",
"b3e3",
"d8d1",
"f3e1",
"d1e1",
"e3e1",
"a5e1",
"... | {
"fen": "r2qk2r/pp2npp1/2n1b2p/b1Bp4/2B5/PQ3N2/1PP2PPP/RN1R2K1 b kq - 3 14",
"pvs": [
{
"score": {
"type": "cp",
"value": -806
},
"moves": [
"d5c4",
"d1d8",
"a8d8",
"b3e3",
"d8d1",
"f3e1",
"d1e1",
"e3e1",
... | [
"dxc4 attacks the queen on b3.",
"After dxc4, White's best reply is Rxd8+.",
"The rook on d1 is not defended.",
"White has a check: Rxd8+.",
"White can capture the knight on e7 with Bxe7.",
"Black threatens cxb3.",
"Black has not castled.",
"Material: equal.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: r2qk2r/pp2npp1/2n1b2p/b1Bp4/2B5/PQ3N2/1PP2PPP/RN1R2K1 b kq - 3 14
Black to move, move 14.
Move played: dxc4.
Verdict: Only move.
Black's winning chances: 95% → 95%.
Best move: dxc4.
Best line: dxc4 Rxd8+ Rxd8 Qe3 Rd1+ Ne1.
Facts:
- dxc4 attacks the queen on b3.
- A... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: r2qk2r/pp2npp1/2n1b2p/b1Bp4/2B5/PQ3N2/1PP2PPP/RN1R2K1 b kq - 3 14
Black to move, move 14.
Move played: dxc4.
Ver... | |
mate | MIT | true | mate_0f435bb8476b7434 | r1r3k1/5pp1/pq2p2B/1p2b3/3n2Q1/P2B1P2/1P3P1P/4R1K1 w - - 0 22 | h6g5 | Bg5 | Shift the piece to a proactive position, where it exerts more influence. Tactical line: Bg5 f5 Qh5 Qc6 Re3 Qd6 | null | null | explain_move | beginner | short | Blunder | {
"fen": "r1r3k1/5pp1/pq2p3/1p2b1B1/3n2Q1/P2B1P2/1P3P1P/4R1K1 b - - 1 22",
"pvs": [
{
"score": {
"type": "cp",
"value": -694
},
"moves": [
"f7f5",
"g4h5",
"b6c7",
"g1h1",
"c7f7",
"h5f7",
"g8f7",
"e1e5",
"d4... | {
"fen": "r1r3k1/5pp1/pq2p2B/1p2b3/3n2Q1/P2B1P2/1P3P1P/4R1K1 w - - 0 22",
"pvs": [
{
"score": {
"type": "cp",
"value": 300
},
"moves": [
"e1e5",
"g8f8",
"h6g7",
"f8e8",
"e5h5",
"d4f5",
"g7f6",
"f5e7",
"d3e4... | [
"After Bg5, Black's best reply is f5.",
"The bishop on e5 is not defended.",
"Black has a check: Ne2+.",
"White threatens Rxe5.",
"Black is up a rook in material.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: r1r3k1/5pp1/pq2p2B/1p2b3/3n2Q1/P2B1P2/1P3P1P/4R1K1 w - - 0 22
White to move, move 22.
Move played: Bg5.
Verdict: Blunder.
White's winning chances: 75% → 7%.
Best move: Rxe5.
Best line: Rxe5 Kf8 Bxg7+ Ke8 Rh5 Nf5.
Facts:
- After Bg5, Black's best reply is f5.
- The ... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: r1r3k1/5pp1/pq2p2B/1p2b3/3n2Q1/P2B1P2/1P3P1P/4R1K1 w - - 0 22
White to move, move 22.
Move played: Bg5.
Verdict:... | |
mate | MIT | true | mate_0f68b1f0f0f0499b | 6k1/pp3pp1/1q5p/8/1P1r4/P2Q4/5PPP/4R1K1 w - - 0 22 | e1e8 | Re8# | Transfer the piece to a lively area, boosting its impact on the board. Tactical line: Re8# Checkmate! | null | null | explain_move | beginner | short | Only move | {
"fen": "4R1k1/pp3pp1/1q5p/8/1P1r4/P2Q4/5PPP/6K1 b - - 1 22",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": []
}
]
} | {
"fen": "6k1/pp3pp1/1q5p/8/1P1r4/P2Q4/5PPP/4R1K1 w - - 0 22",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": [
"e1e8"
]
},
{
"score": {
"type": "cp",
"value": 18
},
"moves": [
"d3f3",
"b6c6",... | [
"The queen on d3 is not defended.",
"Black king is in check on g8.",
"Material: equal.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 6k1/pp3pp1/1q5p/8/1P1r4/P2Q4/5PPP/4R1K1 w - - 0 22
White to move, move 22.
Move played: Re8#.
Verdict: Only move.
White's winning chances: 100% → 100%.
Best move: Re8#.
Best line: Re8#.
Facts:
- The queen on d3 is not defended.
- Black king is in check on g8.
- Mat... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 6k1/pp3pp1/1q5p/8/1P1r4/P2Q4/5PPP/4R1K1 w - - 0 22
White to move, move 22.
Move played: Re8#.
Verdict: Only move... | |
mate | MIT | true | mate_0f6fe18465c4800d | r1b1r1k1/1p4bp/pq3np1/1Np2p2/2P1p3/1P2P1P1/PBQ2PBP/3R1RK1 w - - 0 19 | d1d6 | Rd6 | Move the piece to a pivotal position, providing it with greater board command. Tactical line: Rd6 Qa5 Bc3 axb5 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Only move | {
"fen": "r1b1r1k1/1p4bp/pq1R1np1/1Np2p2/2P1p3/1P2P1P1/PBQ2PBP/5RK1 b - - 1 19",
"pvs": [
{
"score": {
"type": "cp",
"value": 592
},
"moves": [
"f6d7",
"d6b6",
"a6b5",
"b2g7",
"b5b4",
"b6b5",
"b7b6",
"g7b2"
]... | {
"fen": "r1b1r1k1/1p4bp/pq3np1/1Np2p2/2P1p3/1P2P1P1/PBQ2PBP/3R1RK1 w - - 0 19",
"pvs": [
{
"score": {
"type": "cp",
"value": 592
},
"moves": [
"d1d6",
"f6d7",
"d6b6",
"a6b5",
"b2g7",
"b5b4",
"b6b5",
"b7b6",
... | [
"Rd6 attacks the queen on b6.",
"After Rd6, Black's best reply is Nd7.",
"The queen on b6 is not defended.",
"Black can capture the rook on d6 with Qxd6.",
"White threatens Rxb6.",
"Material: equal.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: r1b1r1k1/1p4bp/pq3np1/1Np2p2/2P1p3/1P2P1P1/PBQ2PBP/3R1RK1 w - - 0 19
White to move, move 19.
Move played: Rd6.
Verdict: Only move.
White's winning chances: 90% → 90%.
Best move: Rd6.
Best line: Rd6 Nd7 Rxb6 axb5 Bxg7 b4.
Facts:
- Rd6 attacks the queen on b6.
- Afte... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: r1b1r1k1/1p4bp/pq3np1/1Np2p2/2P1p3/1P2P1P1/PBQ2PBP/3R1RK1 w - - 0 19
White to move, move 19.
Move played: Rd6.
V... | |
mate | MIT | true | mate_0f8b64b06780790d | 8/4k3/4p1p1/3pn1Kp/8/2P3P1/7P/4R3 b - - 11 51 | e5f3 | Nf3+ | Reassign the piece to a central area, where it exercises more control over the board. Tactical line: Nf3+ Kxg6 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Only move | {
"fen": "8/4k3/4p1p1/3p2Kp/8/2P2nP1/7P/4R3 w - - 12 52",
"pvs": [
{
"score": {
"type": "cp",
"value": -441
},
"moves": [
"g5g6",
"f3e1",
"g6h5",
"e7f6",
"h2h4",
"e1f3",
"h5g4",
"f3e5",
"g4h5",
"e5f... | {
"fen": "8/4k3/4p1p1/3pn1Kp/8/2P3P1/7P/4R3 b - - 11 51",
"pvs": [
{
"score": {
"type": "cp",
"value": -441
},
"moves": [
"e5f3",
"g5g6",
"f3e1",
"g6h5",
"e7f6",
"h2h4",
"e1f3",
"h5g4",
"f3e5",
"g4h... | [
"After Nf3+, White's best reply is Kxg6.",
"The rook on e1 is not defended.",
"White king is in check on g5.",
"White is up a pawn in material.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 8/4k3/4p1p1/3pn1Kp/8/2P3P1/7P/4R3 b - - 11 51
Black to move, move 51.
Move played: Nf3+.
Verdict: Only move.
Black's winning chances: 84% → 84%.
Best move: Nf3+.
Best line: Nf3+ Kxg6 Nxe1 Kxh5 Kf6 h4.
Facts:
- After Nf3+, White's best reply is Kxg6.
- The rook on e... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 8/4k3/4p1p1/3pn1Kp/8/2P3P1/7P/4R3 b - - 11 51
Black to move, move 51.
Move played: Nf3+.
Verdict: Only move.
Bla... | |
mate | MIT | true | mate_0f940df4f0a5391e | 2k3rr/ppp1n3/2n2p2/3p1q2/QP1P2Bp/2P4P/P2N1P2/3RR2K b - - 4 21 | a7a6 | a6 | The movement of a black pawn creates additional room on the queenside, giving black more control over piece movement. Tactical line: a6 Bxf5+ Trade the lower value piece for a higher value piece. | null | null | explain_move | club | short | Blunder | {
"fen": "2k3rr/1pp1n3/p1n2p2/3p1q2/QP1P2Bp/2P4P/P2N1P2/3RR2K w - - 0 22",
"pvs": [
{
"score": {
"type": "cp",
"value": 647
},
"moves": [
"g4f5",
"e7f5",
"a4c2",
"c6d4",
"c3d4",
"f5d4",
"c2c5",
"d4e6",
"c5e... | {
"fen": "2k3rr/ppp1n3/2n2p2/3p1q2/QP1P2Bp/2P4P/P2N1P2/3RR2K b - - 4 21",
"pvs": [
{
"score": {
"type": "cp",
"value": -475
},
"moves": [
"g8g4",
"h3g4",
"f5g4",
"h1h2",
"g4f4",
"h2h1",
"e7f5",
"e1f1"
]
}... | [
"After a6, White's best reply is Bxf5+.",
"White has a check: Bxf5+.",
"White can capture the knight on e7 with Rxe7.",
"Material: equal.",
"Phase: middlegame."
] | task: explain_move
level: club
detail: short
FEN: 2k3rr/ppp1n3/2n2p2/3p1q2/QP1P2Bp/2P4P/P2N1P2/3RR2K b - - 4 21
Black to move, move 21.
Move played: a6.
Verdict: Blunder.
Black's winning chances: 85% → 8%.
Best move: Rxg4.
Best line: Rxg4 hxg4 Qxg4 Kh2 Qf4+ Kh1.
Facts:
- After a6, White's best reply is Bxf5+.
- White ... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: club
detail: short
FEN: 2k3rr/ppp1n3/2n2p2/3p1q2/QP1P2Bp/2P4P/P2N1P2/3RR2K b - - 4 21
Black to move, move 21.
Move played: a6.
Verdict: Blun... | |
mate | MIT | true | mate_0f999ad8f72637fc | 5k2/pb4p1/1p1p2p1/2p1n3/4P3/3B3P/PPP1N1P1/6K1 b - - 1 25 | c5c4 | c4 | By pushing a black pawn forward, it opens up the queenside, granting more freedom to maneuver other pieces. Tactical line: c4 Nc1 cxd3 Trade the lower value piece for a higher value piece. | null | null | explain_move | club | short | Only move | {
"fen": "5k2/pb4p1/1p1p2p1/4n3/2p1P3/3B3P/PPP1N1P1/6K1 w - - 0 26",
"pvs": [
{
"score": {
"type": "cp",
"value": -508
},
"moves": [
"e2f4",
"c4d3",
"c2d3",
"f8f7"
]
}
]
} | {
"fen": "5k2/pb4p1/1p1p2p1/2p1n3/4P3/3B3P/PPP1N1P1/6K1 b - - 1 25",
"pvs": [
{
"score": {
"type": "cp",
"value": -508
},
"moves": [
"c5c4",
"e2f4",
"c4d3",
"c2d3",
"f8f7"
]
},
{
"score": {
"type": "cp",
... | [
"c4 attacks the bishop on d3 together with the knight on e5.",
"After c4, White's best reply is Nf4.",
"Black threatens cxd3.",
"Material: equal.",
"Phase: endgame."
] | task: explain_move
level: club
detail: short
FEN: 5k2/pb4p1/1p1p2p1/2p1n3/4P3/3B3P/PPP1N1P1/6K1 b - - 1 25
Black to move, move 25.
Move played: c4.
Verdict: Only move.
Black's winning chances: 87% → 87%.
Best move: c4.
Best line: c4 Nf4 cxd3 cxd3 Kf7.
Facts:
- c4 attacks the bishop on d3 together with the knight on e5... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: club
detail: short
FEN: 5k2/pb4p1/1p1p2p1/2p1n3/4P3/3B3P/PPP1N1P1/6K1 b - - 1 25
Black to move, move 25.
Move played: c4.
Verdict: Only move... | |
mate | MIT | true | mate_0fb4c31c4d961d2a | r1b2k1B/pppp1p1p/2n5/2q2N2/4nP2/8/PPP3PP/R2QKB1R b KQ - 0 12 | c5f2 | Qf2# | Adjust the piece to a key area, where it holds more influence over the board. Tactical line: Qf2# Checkmate! | null | null | explain_move | beginner | short | Only move | {
"fen": "r1b2k1B/pppp1p1p/2n5/5N2/4nP2/8/PPP2qPP/R2QKB1R w KQ - 1 13",
"pvs": [
{
"score": {
"type": "mate",
"value": -1
},
"moves": []
}
]
} | {
"fen": "r1b2k1B/pppp1p1p/2n5/2q2N2/4nP2/8/PPP3PP/R2QKB1R b KQ - 0 12",
"pvs": [
{
"score": {
"type": "mate",
"value": -1
},
"moves": [
"c5f2"
]
},
{
"score": {
"type": "cp",
"value": 105
},
"moves": [
"d7d5",
... | [
"White king is in check on e1.",
"White is up a rook in material.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: r1b2k1B/pppp1p1p/2n5/2q2N2/4nP2/8/PPP3PP/R2QKB1R b KQ - 0 12
Black to move, move 12.
Move played: Qf2#.
Verdict: Only move.
Black's winning chances: 100% → 100%.
Best move: Qf2#.
Best line: Qf2#.
Facts:
- White king is in check on e1.
- White is up a rook in materi... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: r1b2k1B/pppp1p1p/2n5/2q2N2/4nP2/8/PPP3PP/R2QKB1R b KQ - 0 12
Black to move, move 12.
Move played: Qf2#.
Verdict:... | |
mate | MIT | true | mate_0ffbec24c173931f | rqbr1k2/pp2Npbp/2p1p1p1/1RP3Pn/4P3/4BP2/P1PQ3P/4KB1R w K - 2 18 | d2a5 | Qa5 | Displace the piece to a more promising position, strengthening its board authority. Tactical line: Qa5 Kxe7 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Blunder | {
"fen": "rqbr1k2/pp2Npbp/2p1p1p1/QRP3Pn/4P3/4BP2/P1P4P/4KB1R b K - 3 18",
"pvs": [
{
"score": {
"type": "cp",
"value": -668
},
"moves": [
"f8e7",
"b5b3",
"e7e8",
"f1a6",
"g7e5",
"e1g1",
"b7b5",
"c5b6",
"a7... | {
"fen": "rqbr1k2/pp2Npbp/2p1p1p1/1RP3Pn/4P3/4BP2/P1PQ3P/4KB1R w K - 2 18",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": [
"d2d8"
]
},
{
"score": {
"type": "cp",
"value": -168
},
"moves": [
"e7c6",
... | [
"Qa5 attacks the rook on d8.",
"After Qa5, Black's best reply is Kxe7.",
"After Qa5, Black captures the knight on e7 with Kxe7.",
"The knight on e7 is not defended.",
"The rook on d8 is not defended.",
"Black has a check: Bc3+.",
"Black can capture the rook on b5 with cxb5.",
"White threatens Qxd8#.",... | task: explain_move
level: beginner
detail: short
FEN: rqbr1k2/pp2Npbp/2p1p1p1/1RP3Pn/4P3/4BP2/P1PQ3P/4KB1R w K - 2 18
White to move, move 18.
Move played: Qa5.
Verdict: Blunder.
White's winning chances: 100% → 8%.
Best move: Qxd8#.
Best line: Qxd8#.
Facts:
- Qa5 attacks the rook on d8.
- After Qa5, Black's best reply ... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: rqbr1k2/pp2Npbp/2p1p1p1/1RP3Pn/4P3/4BP2/P1PQ3P/4KB1R w K - 2 18
White to move, move 18.
Move played: Qa5.
Verdic... | |
mate | MIT | true | mate_1027f681f4787e51 | 5b1k/6pp/8/p3P3/P7/1P6/2q3PP/1R3RK1 w - - 0 31 | b1c1 | Rbc1 | Move the piece to an aggressive spot, enhancing its control over the board. Tactical line: Rbc1 Bc5+ Kh1 Qe2 Rfe1 Qf2 | null | null | explain_move | beginner | short | Blunder | {
"fen": "5b1k/6pp/8/p3P3/P7/1P6/2q3PP/2R2RK1 b - - 1 31",
"pvs": [
{
"score": {
"type": "cp",
"value": 14
},
"moves": [
"f8c5",
"g1h1",
"c2e2",
"f1e1",
"e2d2",
"e1d1",
"d2f2",
"d1d8",
"c5f8",
"e5e6... | {
"fen": "5b1k/6pp/8/p3P3/P7/1P6/2q3PP/1R3RK1 w - - 0 31",
"pvs": [
{
"score": {
"type": "mate",
"value": 1
},
"moves": [
"f1f8"
]
},
{
"score": {
"type": "cp",
"value": 14
},
"moves": [
"b1c1",
"f8c5",
... | [
"Rbc1 attacks the queen on c2.",
"After Rbc1, Black's best reply is Bc5+.",
"The queen on c2 is not defended.",
"The bishop on f8 is not defended.",
"Black has a check: Qf2+.",
"Black can capture the rook on c1 with Qxc1.",
"White threatens Rxf8#.",
"Material: equal.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 5b1k/6pp/8/p3P3/P7/1P6/2q3PP/1R3RK1 w - - 0 31
White to move, move 31.
Move played: Rbc1.
Verdict: Blunder.
White's winning chances: 100% → 51%.
Best move: Rxf8#.
Best line: Rxf8#.
Facts:
- Rbc1 attacks the queen on c2.
- After Rbc1, Black's best reply is Bc5+.
- T... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 5b1k/6pp/8/p3P3/P7/1P6/2q3PP/1R3RK1 w - - 0 31
White to move, move 31.
Move played: Rbc1.
Verdict: Blunder.
Whit... | |
mate | MIT | true | mate_10341686f728e64e | 8/1b4pp/4p3/4P3/2P2PkP/P3K3/1P6/8 w - - 3 32 | b2b4 | b4 | By moving a white pawn forward, the queenside becomes more spacious, offering more opportunities to move pieces freely. Tactical line: b4 Kxh4 Trade the lower value piece for a higher value piece. | null | null | explain_move | club | short | Best | {
"fen": "8/1b4pp/4p3/4P3/1PP2PkP/P3K3/8/8 b - - 0 32",
"pvs": [
{
"score": {
"type": "cp",
"value": 150
},
"moves": [
"b7g2",
"b4b5",
"g4h4",
"c4c5"
]
}
]
} | {
"fen": "8/1b4pp/4p3/4P3/2P2PkP/P3K3/1P6/8 w - - 3 32",
"pvs": [
{
"score": {
"type": "cp",
"value": 150
},
"moves": [
"b2b4",
"b7g2",
"b4b5",
"g4h4",
"c4c5"
]
},
{
"score": {
"type": "cp",
"value": 23... | [
"After b4, Black's best reply is Bg2.",
"Material: equal.",
"Phase: endgame."
] | task: explain_move
level: club
detail: short
FEN: 8/1b4pp/4p3/4P3/2P2PkP/P3K3/1P6/8 w - - 3 32
White to move, move 32.
Move played: b4.
Verdict: Best.
White's winning chances: 63% → 63%.
Best move: b4.
Best line: b4 Bg2 b5 Kxh4 c5.
Facts:
- After b4, Black's best reply is Bg2.
- Material: equal.
- Phase: endgame. | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: club
detail: short
FEN: 8/1b4pp/4p3/4P3/2P2PkP/P3K3/1P6/8 w - - 3 32
White to move, move 32.
Move played: b4.
Verdict: Best.
White's winning... | |
mate | MIT | true | mate_104083f5dcd3581a | r4kr1/ppp1n3/3p4/3Pp2p/2P1N3/5p1q/PPQ3P1/R1B2RK1 b - - 0 19 | g8g2 | Rxg2+ | Sacrifice a piece to open a channel or diagonal near the opponent's king Tactical line: Rxg2+ Qxg2 Qxg2# Checkmate! | null | null | explain_move | club | short | Only move | {
"fen": "r4k2/ppp1n3/3p4/3Pp2p/2P1N3/5p1q/PPQ3r1/R1B2RK1 w - - 0 20",
"pvs": [
{
"score": {
"type": "mate",
"value": -2
},
"moves": [
"c2g2",
"h3g2"
]
}
]
} | {
"fen": "r4kr1/ppp1n3/3p4/3Pp2p/2P1N3/5p1q/PPQ3P1/R1B2RK1 b - - 0 19",
"pvs": [
{
"score": {
"type": "mate",
"value": -2
},
"moves": [
"g8g2",
"c2g2",
"h3g2"
]
},
{
"score": {
"type": "cp",
"value": 170
},
... | [
"After Rxg2+, White's best reply is Qxg2.",
"The queen on c2 is not defended.",
"White can capture the rook on g2 with Qxg2.",
"White king is in check on g1.",
"White is up a pawn in material.",
"Phase: middlegame."
] | task: explain_move
level: club
detail: short
FEN: r4kr1/ppp1n3/3p4/3Pp2p/2P1N3/5p1q/PPQ3P1/R1B2RK1 b - - 0 19
Black to move, move 19.
Move played: Rxg2+.
Verdict: Only move.
Black's winning chances: 100% → 100%.
Best move: Rxg2+.
Best line: Rxg2+ Qxg2 Qxg2#.
Facts:
- After Rxg2+, White's best reply is Qxg2.
- The quee... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: club
detail: short
FEN: r4kr1/ppp1n3/3p4/3Pp2p/2P1N3/5p1q/PPQ3P1/R1B2RK1 b - - 0 19
Black to move, move 19.
Move played: Rxg2+.
Verdict: Onl... | |
mate | MIT | true | mate_11465a99d426913b | r2q1rk1/ppp2ppp/3b1n2/1B6/3QP3/2N2P1P/PPP2P2/R1B2RK1 b - - 0 11 | d6h2 | Bh2+ | Settle the piece in a more energetic spot, where it has better board supervision. Tactical line: Bh2+ Kxh2 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Only move | {
"fen": "r2q1rk1/ppp2ppp/5n2/1B6/3QP3/2N2P1P/PPP2P1b/R1B2RK1 w - - 1 12",
"pvs": [
{
"score": {
"type": "cp",
"value": -261
},
"moves": [
"g1h2",
"d8d4",
"c1e3",
"d4b4",
"a1b1",
"c7c6",
"b5d3",
"f6h5",
"f3... | {
"fen": "r2q1rk1/ppp2ppp/3b1n2/1B6/3QP3/2N2P1P/PPP2P2/R1B2RK1 b - - 0 11",
"pvs": [
{
"score": {
"type": "cp",
"value": -261
},
"moves": [
"d6h2",
"g1h2",
"d8d4",
"c1e3",
"d4b4",
"a1b1",
"c7c6",
"b5d3",
"f... | [
"After Bh2+, White's best reply is Kxh2.",
"The bishop on h2 is not defended.",
"The queen on d4 is not defended.",
"White can capture the bishop on h2 with Kxh2.",
"White king is in check on g1.",
"White is up a minor piece and a pawn in material.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: r2q1rk1/ppp2ppp/3b1n2/1B6/3QP3/2N2P1P/PPP2P2/R1B2RK1 b - - 0 11
Black to move, move 11.
Move played: Bh2+.
Verdict: Only move.
Black's winning chances: 72% → 72%.
Best move: Bh2+.
Best line: Bh2+ Kxh2 Qxd4 Be3 Qb4 Rab1.
Facts:
- After Bh2+, White's best reply is Kx... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: r2q1rk1/ppp2ppp/3b1n2/1B6/3QP3/2N2P1P/PPP2P2/R1B2RK1 b - - 0 11
Black to move, move 11.
Move played: Bh2+.
Verdi... | |
mate | MIT | true | mate_11590b9c7468307e | 8/5pp1/5k1p/5P2/4K1P1/7P/8/8 b - - 0 44 | f6g5 | Kg5 | Plant the piece in a dominant spot, expanding its control over the board. Tactical line: Kg5 Ke5 g6 f6 h5 h4+ | null | null | explain_move | beginner | short | Only move | {
"fen": "8/5pp1/7p/5Pk1/4K1P1/7P/8/8 w - - 1 45",
"pvs": [
{
"score": {
"type": "cp",
"value": -249
},
"moves": [
"e4e5",
"g7g6",
"h3h4",
"g5g4",
"f5f6",
"g6g5",
"e5d6",
"g5h4",
"d6e7",
"h4h3",
... | {
"fen": "8/5pp1/5k1p/5P2/4K1P1/7P/8/8 b - - 0 44",
"pvs": [
{
"score": {
"type": "cp",
"value": -249
},
"moves": [
"f6g5",
"e4e5",
"g7g6",
"h3h4",
"g5g4",
"f5f6",
"g6g5",
"e5d6",
"g5h4",
"d6e7",
... | [
"After Kg5, White's best reply is Ke5.",
"White has a check: h4+.",
"Material: equal.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 8/5pp1/5k1p/5P2/4K1P1/7P/8/8 b - - 0 44
Black to move, move 44.
Move played: Kg5.
Verdict: Only move.
Black's winning chances: 71% → 71%.
Best move: Kg5.
Best line: Kg5 Ke5 g6 h4+ Kxg4 f6.
Facts:
- After Kg5, White's best reply is Ke5.
- White has a check: h4+.
- M... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 8/5pp1/5k1p/5P2/4K1P1/7P/8/8 b - - 0 44
Black to move, move 44.
Move played: Kg5.
Verdict: Only move.
Black's wi... | |
mate | MIT | true | mate_11c1b0791c7accf3 | 8/1b3r1k/p2q2pp/1p6/3b1pQ1/P2B2P1/2P2P2/4R1K1 w - - 2 36 | e1e6 | Re6 | Plant the piece in a dominant spot, expanding its control over the board. Tactical line: Re6 Bxf2+ Kf1 Rf6 Rxd6 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Only move | {
"fen": "8/1b3r1k/p2qR1pp/1p6/3b1pQ1/P2B2P1/2P2P2/6K1 b - - 3 36",
"pvs": [
{
"score": {
"type": "cp",
"value": 182
},
"moves": [
"d6d7",
"d3g6",
"h7g8",
"g6f7",
"g8f7",
"g4g6",
"f7f8",
"g6h6",
"f8g8"
... | {
"fen": "8/1b3r1k/p2q2pp/1p6/3b1pQ1/P2B2P1/2P2P2/4R1K1 w - - 2 36",
"pvs": [
{
"score": {
"type": "cp",
"value": 182
},
"moves": [
"e1e6",
"d6d7",
"d3g6",
"h7g8",
"g6f7",
"g8f7",
"g4g6",
"f7f8",
"g6h6",
... | [
"Re6 attacks the queen on d6.",
"After Re6, Black's best reply is Qd7.",
"The queen on d6 is not defended.",
"Black has a check: Bxf2+.",
"Black can capture the rook on e6 with Qxe6.",
"White threatens Rxd6.",
"Black is up a minor piece and a pawn in material.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: 8/1b3r1k/p2q2pp/1p6/3b1pQ1/P2B2P1/2P2P2/4R1K1 w - - 2 36
White to move, move 36.
Move played: Re6.
Verdict: Only move.
White's winning chances: 66% → 66%.
Best move: Re6.
Best line: Re6 Qd7 Bxg6+ Kg8 Bxf7+ Kxf7.
Facts:
- Re6 attacks the queen on d6.
- After Re6, Bl... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 8/1b3r1k/p2q2pp/1p6/3b1pQ1/P2B2P1/2P2P2/4R1K1 w - - 2 36
White to move, move 36.
Move played: Re6.
Verdict: Only... | |
mate | MIT | true | mate_1249b3f485c76edc | 3r2k1/1b1r1ppp/ppq5/8/2pp4/P1P1QN2/1P3PPP/3RR1K1 w - - 0 25 | e3e8 | Qe8+ | Switch the piece to a more advantageous place, increasing its mastery over the board. Tactical line: Qe8+ Rxe8 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Only move | {
"fen": "3rQ1k1/1b1r1ppp/ppq5/8/2pp4/P1P2N2/1P3PPP/3RR1K1 b - - 1 25",
"pvs": [
{
"score": {
"type": "mate",
"value": 2
},
"moves": [
"d8e8",
"e1e8"
]
}
]
} | {
"fen": "3r2k1/1b1r1ppp/ppq5/8/2pp4/P1P1QN2/1P3PPP/3RR1K1 w - - 0 25",
"pvs": [
{
"score": {
"type": "mate",
"value": 2
},
"moves": [
"e3e8",
"d8e8",
"e1e8"
]
},
{
"score": {
"type": "cp",
"value": -69
},
... | [
"After Qe8+, Black's best reply is Rxe8.",
"Black can capture the queen on e8 with Rxe8.",
"Black king is in check on g8.",
"Black is up a pawn in material.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: 3r2k1/1b1r1ppp/ppq5/8/2pp4/P1P1QN2/1P3PPP/3RR1K1 w - - 0 25
White to move, move 25.
Move played: Qe8+.
Verdict: Only move.
White's winning chances: 100% → 100%.
Best move: Qe8+.
Best line: Qe8+ Rxe8 Rxe8#.
Facts:
- After Qe8+, Black's best reply is Rxe8.
- Black ca... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 3r2k1/1b1r1ppp/ppq5/8/2pp4/P1P1QN2/1P3PPP/3RR1K1 w - - 0 25
White to move, move 25.
Move played: Qe8+.
Verdict: ... | |
mate | MIT | true | mate_124c5dab0c2b75fa | 5rk1/ppp2ppp/1b6/1Q1Pq3/P7/5BP1/1P3P1P/1R4K1 b - - 0 26 | e5d4 | Qd4 | Advance the piece to a strategic square, optimizing its control over the board. Tactical line: Qd4 Rf1 Rb8 Kg2 Rd8 b3 | null | null | explain_move | beginner | short | Blunder | {
"fen": "5rk1/ppp2ppp/1b6/1Q1P4/P2q4/5BP1/1P3P1P/1R4K1 w - - 1 27",
"pvs": [
{
"score": {
"type": "cp",
"value": -6
},
"moves": [
"b1f1",
"a7a6",
"b5b3",
"f8b8",
"g1g2",
"b6c5",
"d5d6",
"d4d6"
]
}
]
} | {
"fen": "5rk1/ppp2ppp/1b6/1Q1Pq3/P7/5BP1/1P3P1P/1R4K1 b - - 0 26",
"pvs": [
{
"score": {
"type": "cp",
"value": -592
},
"moves": [
"e5f5",
"b1f1",
"f5f3",
"a4a5",
"b6d4",
"b5b4",
"d4f6",
"b4b7",
"a7a6",
... | [
"After Qd4, White's best reply is Rf1.",
"White can capture the bishop on b6 with Qxb6.",
"Black threatens Qxf2+.",
"Material: equal.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 5rk1/ppp2ppp/1b6/1Q1Pq3/P7/5BP1/1P3P1P/1R4K1 b - - 0 26
Black to move, move 26.
Move played: Qd4.
Verdict: Blunder.
Black's winning chances: 90% → 51%.
Best move: Qf5.
Best line: Qf5 Rf1 Qxf3 a5 Bd4 Qb4.
Facts:
- After Qd4, White's best reply is Rf1.
- White can ca... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 5rk1/ppp2ppp/1b6/1Q1Pq3/P7/5BP1/1P3P1P/1R4K1 b - - 0 26
Black to move, move 26.
Move played: Qd4.
Verdict: Blund... | |
mate | MIT | true | mate_1268fadf125254a2 | 8/7k/2b1p1pp/4P2n/1p6/6PP/1rBR1P1K/6N1 w - - 0 40 | c2g6 | Bxg6+ | Give up a piece to gain access to a file or diagonal near the enemy king Tactical line: Bxg6+ Kxg6 Trade the lower value piece for a higher value piece. | null | null | explain_move | club | short | Only move | {
"fen": "8/7k/2b1p1Bp/4P2n/1p6/6PP/1r1R1P1K/6N1 b - - 0 40",
"pvs": [
{
"score": {
"type": "cp",
"value": 603
},
"moves": [
"h7g6",
"d2b2",
"b4b3",
"b2b3",
"h5g7",
"g1e2",
"c6d5"
]
}
]
} | {
"fen": "8/7k/2b1p1pp/4P2n/1p6/6PP/1rBR1P1K/6N1 w - - 0 40",
"pvs": [
{
"score": {
"type": "cp",
"value": 603
},
"moves": [
"c2g6",
"h7g6",
"d2b2",
"b4b3",
"b2b3",
"h5g7",
"g1e2",
"c6d5"
]
},
{
... | [
"After Bxg6+, Black's best reply is Kxg6.",
"The rook on b2 is not defended.",
"The rook on d2 is not defended.",
"Black can capture the bishop on g6 with Kxg6.",
"Black king is in check on h7.",
"Material: equal.",
"Phase: endgame."
] | task: explain_move
level: club
detail: short
FEN: 8/7k/2b1p1pp/4P2n/1p6/6PP/1rBR1P1K/6N1 w - - 0 40
White to move, move 40.
Move played: Bxg6+.
Verdict: Only move.
White's winning chances: 90% → 90%.
Best move: Bxg6+.
Best line: Bxg6+ Kxg6 Rxb2 b3 Rxb3 Ng7.
Facts:
- After Bxg6+, Black's best reply is Kxg6.
- The rook ... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: club
detail: short
FEN: 8/7k/2b1p1pp/4P2n/1p6/6PP/1rBR1P1K/6N1 w - - 0 40
White to move, move 40.
Move played: Bxg6+.
Verdict: Only move.
Wh... | |
mate | MIT | true | mate_1342b3190370b99f | 2k4r/pp1r1pbp/1n1p2p1/2p3N1/b3R3/2Pq1B2/P2B1PPP/1RQ3K1 w - - 4 21 | c1e1 | Qe1 | Move the piece to a pivotal position, providing it with greater board command. Tactical line: Qe1 d5 Rh4 Nc4 Be3 Bc2 | null | null | explain_move | beginner | short | Blunder | {
"fen": "2k4r/pp1r1pbp/1n1p2p1/2p3N1/b3R3/2Pq1B2/P2B1PPP/1R2Q1K1 b - - 5 21",
"pvs": [
{
"score": {
"type": "cp",
"value": -246
},
"moves": [
"a4c6",
"e4e3",
"d3c4",
"f3c6",
"b7c6",
"h2h4"
]
}
]
} | {
"fen": "2k4r/pp1r1pbp/1n1p2p1/2p3N1/b3R3/2Pq1B2/P2B1PPP/1RQ3K1 w - - 4 21",
"pvs": [
{
"score": {
"type": "cp",
"value": 156
},
"moves": [
"b1b6",
"a7b6",
"e4a4",
"b6b5",
"a4e4",
"h7h6",
"e4e3",
"d3c4",
"... | [
"After Qe1, Black's best reply is Bc6.",
"Black has a check: Qf1+.",
"Black can capture the rook on b1 with Qxb1.",
"White threatens Re8+.",
"Black is up two pawns.",
"Phase: middlegame."
] | task: explain_move
level: beginner
detail: short
FEN: 2k4r/pp1r1pbp/1n1p2p1/2p3N1/b3R3/2Pq1B2/P2B1PPP/1RQ3K1 w - - 4 21
White to move, move 21.
Move played: Qe1.
Verdict: Blunder.
White's winning chances: 64% → 29%.
Best move: Rxb6.
Best line: Rxb6 axb6 Rxa4 b5 Re4 h6.
Facts:
- After Qe1, Black's best reply is Bc6.
- ... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 2k4r/pp1r1pbp/1n1p2p1/2p3N1/b3R3/2Pq1B2/P2B1PPP/1RQ3K1 w - - 4 21
White to move, move 21.
Move played: Qe1.
Verd... | |
mate | MIT | true | mate_1387e7ae3d4db385 | 6rk/pb5p/5P1R/2p4q/8/6Q1/PP5K/8 w - - 4 40 | h6h5 | Rxh5 | Exchange a lower-valued piece for a more valuable one, and secure an advantage. Tactical line: Rxh5 Rxg3 Trade the lower value piece for a higher value piece. | null | null | explain_move | beginner | short | Only move | {
"fen": "6rk/pb5p/5P2/2p4R/8/6Q1/PP5K/8 b - - 0 40",
"pvs": [
{
"score": {
"type": "cp",
"value": 660
},
"moves": [
"g8g3",
"h2g3",
"c5c4",
"h5c5",
"h8g8",
"c5c4",
"b7c6",
"c4c6"
]
}
]
} | {
"fen": "6rk/pb5p/5P1R/2p4q/8/6Q1/PP5K/8 w - - 4 40",
"pvs": [
{
"score": {
"type": "cp",
"value": 660
},
"moves": [
"h6h5",
"g8g3",
"h2g3",
"c5c4",
"h5c5",
"h8g8",
"c5c4",
"b7c6",
"c4c6"
]
},
... | [
"After Rxh5, Black's best reply is Rxg3.",
"Black can capture the queen on g3 with Rxg3.",
"White threatens Qg7+.",
"Black is up a bishop.",
"Phase: endgame."
] | task: explain_move
level: beginner
detail: short
FEN: 6rk/pb5p/5P1R/2p4q/8/6Q1/PP5K/8 w - - 4 40
White to move, move 40.
Move played: Rxh5.
Verdict: Only move.
White's winning chances: 92% → 92%.
Best move: Rxh5.
Best line: Rxh5 Rxg3 Kxg3 c4 Rc5 Kg8.
Facts:
- After Rxh5, Black's best reply is Rxg3.
- Black can capture... | <|im_start|>system
You are Second, a chess assistant. You explain chess positions and moves clearly using the provided facts.<|im_end|>
<|im_start|>user
task: explain_move
level: beginner
detail: short
FEN: 6rk/pb5p/5P1R/2p4q/8/6Q1/PP5K/8 w - - 4 40
White to move, move 40.
Move played: Rxh5.
Verdict: Only move.
White'... |
End of preview. Expand in Data Studio
Dataset Card for second-chess/second-data-1.0
1. Dataset Summary
second-data-1.0 provides the training, validation, test-pool, and reinforcement learning (RL) prompt splits for Second. Second is a family of small language models based on Qwen 3.5. These models turn Stockfish evaluations and board facts into clear human explanations.
Every record uses the Phase 1 prompt format from core/python and core/ts. Stockfish calculates all tactical and positional facts at fixed depth with MultiPV=3. The language model does not calculate variations on its own. Instead, the model explains the Stockfish facts for beginner (under 1200 Elo) and club (1200–2000 Elo) players. Explanations use short (2–4 sentences, up to 80 words) or long (80–200 words) detail.
2. Data Sources and Licenses
The pipeline follows the license rules in docs/data_sources.md:
| Data Source | License | Redistribution Policy | Public HF Export (data/processed/public/) |
Local Rebuild (data/processed/) |
|---|---|---|---|---|
Lichess Open Game Database (data/sources/lichess_games.py) |
CC0 1.0 Universal | Full public domain rights. | Yes (rl_prompts.*) |
Yes (rl_prompts.*) |
MATE Dataset (data/sources/mate.py, Wang et al., NAACL 2025) |
MIT License | Permissive redistribution with MIT notice. | Yes (sft_*.parquet, sft_*.jsonl) |
Yes (sft_*.parquet, sft_*.jsonl) |
Lichess Studies (Open License) (data/sources/lichess_studies.py) |
CC0 / CC-BY / Public Domain | Redistribute when an open license exists. | Yes (open-license subset) | Yes |
Lichess Studies (Standard ToS) (data/sources/lichess_studies.py) |
Lichess Terms of Service | Author holds copyright. Do not redistribute text. | No (rebuild script only) | Yes |
GameKnot Annotated Games (data/sources/gameknot.py) |
Proprietary (GameKnot EULA) | Do not redistribute commentary text. | No (rebuild script only) | Yes |
MIT License Notice for MATE Dataset Portion
The supervised fine-tuning (SFT) splits include records from OutFlankShu/MATE_DATASET (Wang et al., NAACL 2025). The authors release the MATE dataset under the MIT License:
Copyright (c) 2024 OutFlankShu (MATE Dataset Authors) Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
3. Pipeline Filter Counts (Phase 2.3 & 2.4)
The collectors extracted 16,000 raw human commentary records from GameKnot (6,000), Lichess Studies (6,000), and the MATE dataset (4,000). Stockfish analyzed unique positions at depth=12 and MultiPV=3. The pipeline stored 47,876 unique FEN evaluations in data/cache/stockfish_eval_cache.parquet.
The filter module (data/pipeline/filter_comments.py) runs seven checks in order on each raw comment:
| Filter Stage | Description | Items Removed | Share of Raw Input |
|---|---|---|---|
| Total Raw Input | Raw extracted (position, move, comment) records |
16,000 | 100.0% |
1. cleaned_empty_or_short |
Fewer than 8 words remain after stripping PGN tags, move numbers, and glyphs | 4,165 | 26.0% |
2. not_english |
langdetect (seed=0) identifies non-English text |
134 | 0.8% |
3. no_chess_content |
Text lacks piece names, square coordinates, SAN moves, or chess terms | 931 | 5.8% |
4. illegal_move_or_wrong_piece |
Text names an illegal SAN move or puts a piece on the wrong square (rewards/checks.py) |
4,164 | 26.0% |
5. tone_disagrees_with_verdict |
Praise appears on an error move, or criticism appears on a good move | 191 | 1.2% |
6. links_usernames_offensive |
Text contains URLs, @username handles, or profanity |
69 | 0.4% |
7. duplicate |
Text matches an earlier fingerprint or 4-gram shingle set (Jaccard >= 0.8) | 152 | 1.0% |
| Total Kept Examples | Clean human commentary (6,107 short + 87 long) |
6,194 | 38.7% |
4. Dataset Splits and Distributions (Phase 2.5 & 2.6)
4.1 SFT Splits (Split Strictly by Game)
The split module (data/pipeline/splits.py) groups records by the SHA-256 hash of game_id. If a 4-field normalized FEN in val or test_pool also appears in train, the split module removes that record (66 colliding opening records removed). Therefore, train, val, and test_pool share zero games and zero board positions.
| Partition | Total Records (Local Rebuild) | Public Redistributable Records (public/) |
|---|---|---|
sft_train |
5,659 | 973 |
sft_val (~2.3%) |
138 | 16 |
sft_test_pool (~5.4%) |
331 | 86 |
| Total SFT | 6,128 | 1,075 |
4.2 RL Prompt Set (rl_prompts)
The Lichess collector (data/sources/lichess_games.py) sampled 25,000 positions from rated CC0 Lichess games. More than 80% of these games have an average player Elo between 800 and 2000. The RL prompt generator (data/pipeline/rl_prompts.py) removed all games and 4-field FENs that appear in sft_val or sft_test_pool. Stockfish analyzed the remaining positions at depth=12 and MultiPV=3 to build 20,000 RL prompts:
| Category | Count | Share | Target in PLAN.md |
|---|---|---|---|
| Total RL Prompts | 20,000 | 100.0% | 20k–50k |
Task: explain_move (Inaccuracy / Mistake / Blunder) |
9,000 | 45.0% | ~45% |
Task: explain_move (Good / Best / Only move) |
7,000 | 35.0% | ~35% |
Task: explain_position |
4,000 | 20.0% | ~20% |
Level: beginner |
10,000 | 50.0% | 50% |
Level: club |
10,000 | 50.0% | 50% |
Detail: short |
16,000 | 80.0% | 80% |
Detail: long |
4,000 | 20.0% | 20% |
5. Rebuilding the Full Dataset Locally
To rebuild the full dataset on your local machine or Google Colab, run these commands:
# 1. Collect raw sources
python -m data.sources.gameknot --output data/raw/gameknot.jsonl --max-items 6000
python -m data.sources.lichess_studies --output data/raw/lichess_studies.jsonl --max-items 6000 --include-all-studies
python -m data.sources.mate --output data/raw/mate.jsonl --max-items 4000
cat data/raw/gameknot.jsonl data/raw/lichess_studies.jsonl data/raw/mate.jsonl > data/raw/sft_combined.jsonl
# 2. Sample CC0 Lichess games for RL
python -m data.sources.lichess_games --output data/raw/lichess_games.jsonl --max-positions 25000
# 3. Run Stockfish analysis, filtering, splitting, and export
python -m data.pipeline.run_pipeline \
--sft-input data/raw/sft_combined.jsonl \
--rl-input data/raw/lichess_games.jsonl \
--depth 12 \
--workers 12 \
--rl-target-count 20000
6. Known Limitations
- Human Commentary Grounding: Human authors wrote their comments without seeing our Stockfish
Facts:lines. Phase 2.3 removes comments with illegal moves, wrong piece squares, or mismatched verdict tone. However, SFT mainly teaches explanation style and format. Phase 6 GRPO reinforcement learning enforces strict factual grounding. - Long Commentary Scarcity: Most human move annotations are short (15–50 words). Only 1.4% of filtered human comments exceed 80 words (
detail: long). To balance this, the RL prompt set includes 20%detail: longprompts (4,000prompts). GRPO RL trains thelongmode directly with the length reward check. - Engine Depth: The bulk pipeline runs Stockfish 18 at
depth=12andMultiPV=3. It caches evaluations by FEN in Parquet format. If you run the pipeline with--depth 18, the cache updates the shallow entries automatically.
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