Datasets:

khoilamalphaai
/

chess-coach-benchmark

scenario_id string	model string	condition string	tier string	phase string	severity string	rec_san string	rec_uci string	produced_nonempty bool	move_parseable bool	move_sound bool	no_engine_speak bool	ply_cap_ok bool	engine_speak_hits list	n_violations int64	fabricated bool	violations list
WV60r7W7_20	base	ungrounded	beginner	opening	inaccuracy	Qxb2	b4b2	true	true	false	true	true	[]	0	false	[]
WV60r7W7_20	base	grounded	beginner	opening	inaccuracy	Qxd2	b4d2	true	true	true	true	true	[]	2	true	[ { "sentence": "After this, the queen is on d2, and the knight is on c6, which is a good development.", "reason": "no knight on c6" }, { "sentence": "The key idea is that after Qxd2, the queen is on d2, and the knight is on c6, which is a good position to support the center and attack the pawn on d4....
wQETE7HC_30	base	ungrounded	intermediate	middlegame	blunder	null	null	true	false	false	true	true	[]	1	true	[ { "sentence": "The bishop on b8 is a weak point for the white pieces, and it gives the opponent a good square to play on.", "reason": "no bishop on b8" } ]
wQETE7HC_30	base	grounded	intermediate	middlegame	blunder	a5	a7a5	true	true	true	true	true	[]	0	false	[]
JDukuYVy_26	base	ungrounded	advanced	middlegame	mistake	null	null	true	false	false	true	true	[]	0	false	[]
JDukuYVy_26	base	grounded	advanced	middlegame	mistake	Nd4+	c6d4	true	true	true	true	true	[]	0	false	[]
mr9QjWOC_23	base	ungrounded	beginner	opening	inaccuracy	Qb3	a4b3	true	true	false	true	true	[]	0	false	[]
mr9QjWOC_23	base	grounded	beginner	opening	inaccuracy	Qc4+	a4c4	true	true	true	true	true	[]	0	false	[]
VsykaIN0_82	base	ungrounded	advanced	endgame	inaccuracy	f6	f7f6	true	true	false	true	true	[]	0	false	[]
VsykaIN0_82	base	grounded	advanced	endgame	inaccuracy	Kf6	g6f6	true	true	true	true	true	[]	0	false	[]
GEHbHVSu_23	base	ungrounded	beginner	opening	blunder	null	null	true	false	false	true	true	[]	0	false	[]
GEHbHVSu_23	base	grounded	beginner	opening	blunder	cxb4	c3b4	true	true	true	true	true	[]	0	false	[]
FyeMju3V_32	base	ungrounded	intermediate	middlegame	mistake	null	null	true	false	false	true	true	[]	0	false	[]
FyeMju3V_32	base	grounded	intermediate	middlegame	mistake	O-O-O	e8c8	true	true	true	true	true	[]	0	false	[]
X1nwiPgj_124	base	ungrounded	advanced	endgame	inaccuracy	null	null	true	false	false	true	true	[]	2	true	[ { "sentence": "Your move was a mistake because it left your queen in a weak position and gave the white king a good target.", "reason": "Black has no queen" }, { "sentence": "Takeaway: Always look to control the queen's life square and create a plan that can exploit your opponent's queen.", "rea...
X1nwiPgj_124	base	grounded	advanced	endgame	inaccuracy	Ra4	f4a4	true	true	true	true	true	[]	0	false	[]
dQtHL9Sm_19	base	ungrounded	beginner	opening	blunder	Bxa6	b7a6	true	true	false	true	true	[]	1	true	[ { "sentence": "So instead of playing Bxa6, you should take the queen on b1.", "reason": "no queen on b1" } ]
dQtHL9Sm_19	base	grounded	beginner	opening	blunder	Bc6+	b7c6	true	true	true	true	true	[]	0	false	[]
p8rjXmuV_127	base	ungrounded	intermediate	endgame	blunder	f6	f5f6	true	true	true	true	true	[]	1	true	[ { "sentence": "Takeaway: Focus on controlling the center and using your queen to create threats.", "reason": "White has no queen" } ]
p8rjXmuV_127	base	grounded	intermediate	endgame	blunder	f6	f5f6	true	true	true	true	true	[]	0	false	[]
on8IPGis_102	base	ungrounded	advanced	endgame	blunder	null	null	true	false	false	true	true	[]	1	true	[ { "sentence": "After your queen jump to h5, the queen is now in a vulnerable position.", "reason": "Black has no queen" } ]
on8IPGis_102	base	grounded	advanced	endgame	blunder	Rc6	h6c6	true	true	false	true	true	[]	1	true	[ { "sentence": "Instead, Rc6 targets the Black queen, putting pressure on the center and creating a strong threat.", "reason": "Black has no queen" } ]
9M8bagRc_36	base	ungrounded	beginner	middlegame	blunder	f6	f7f6	true	true	false	true	true	[]	0	false	[]
9M8bagRc_36	base	grounded	beginner	middlegame	blunder	f6	f7f6	true	true	false	true	true	[]	0	false	[]
gX6VnH5e_90	base	ungrounded	intermediate	endgame	mistake	f3	f4f3	true	true	true	true	true	[]	0	false	[]
gX6VnH5e_90	base	grounded	intermediate	endgame	mistake	f3	f4f3	true	true	true	true	true	[]	1	true	[ { "sentence": "After f3, the queen should be on a3, and the bishop on h3, which prepares for a strong attack on the king.", "reason": "no bishop on h3" } ]
kS9EYmmd_29	base	ungrounded	advanced	middlegame	inaccuracy	null	null	true	false	false	true	true	[]	0	false	[]
kS9EYmmd_29	base	grounded	advanced	middlegame	inaccuracy	h3	h2h3	true	true	true	true	true	[]	0	false	[]
JELmIw3g_46	base	ungrounded	intermediate	middlegame	blunder	null	null	true	false	false	true	true	[]	0	false	[]
JELmIw3g_46	base	grounded	intermediate	middlegame	blunder	Qxg2+	g3g2	true	true	true	true	true	[]	0	false	[]
MCcHaWiK_87	base	ungrounded	beginner	endgame	inaccuracy	h5+	h4h5	true	true	true	true	true	[]	1	true	[ { "sentence": "Takeaway: Always develop your queen to a strong square before pushing it forward.", "reason": "White has no queen" } ]
MCcHaWiK_87	base	grounded	beginner	endgame	inaccuracy	a5	a4a5	true	true	true	true	true	[]	0	false	[]
nHtMHeCg_62	base	ungrounded	intermediate	middlegame	blunder	Rxc3	c8c3	true	true	false	true	true	[]	0	false	[]
nHtMHeCg_62	base	grounded	intermediate	middlegame	blunder	Qb3	b1b3	true	true	true	true	true	[]	0	false	[]
taxYHqfB_50	base	ungrounded	advanced	middlegame	mistake	null	null	true	false	false	true	true	[]	0	false	[]
taxYHqfB_50	base	grounded	advanced	middlegame	mistake	Rd6	d8d6	true	true	false	true	true	[]	0	false	[]
utEv6duM_19	base	ungrounded	beginner	opening	blunder	d5	d4d5	true	true	false	true	true	[]	0	false	[]
utEv6duM_19	base	grounded	beginner	opening	blunder	Nf3	g1f3	true	true	true	true	true	[]	0	false	[]
oGYeCz2i_55	base	ungrounded	advanced	middlegame	inaccuracy	null	null	true	false	false	true	true	[]	0	false	[]
oGYeCz2i_55	base	grounded	advanced	middlegame	inaccuracy	Qf2	f1f2	true	true	true	true	true	[]	0	false	[]
WHYrPHwJ_32	base	ungrounded	beginner	middlegame	mistake	Ndb4	d5b4	true	true	true	true	true	[]	1	true	[ { "sentence": "The knight on d4 is not well placed, and it doesn't directly threaten anything.", "reason": "no knight on d4" } ]
WHYrPHwJ_32	base	grounded	beginner	middlegame	mistake	Nf4	d5f4	true	true	true	true	true	[]	0	false	[]
xmqgA3yw_113	base	ungrounded	intermediate	endgame	blunder	null	null	true	false	false	true	true	[]	1	true	[ { "sentence": "Your move was a mistake because it left your queen in a weak position and gave the opponent a good chance to respond.", "reason": "White has no queen" } ]
xmqgA3yw_113	base	grounded	intermediate	endgame	blunder	Kd6	e6d6	true	true	true	true	true	[]	1	true	[ { "sentence": "The real mistake is that the king is too close to the queen, and the bishop is on h4, which is a weak square.", "reason": "no bishop on h4" } ]
flY6Tk8T_19	base	ungrounded	advanced	opening	mistake	Qb3	a4b3	true	true	false	true	true	[]	0	false	[]
flY6Tk8T_19	base	grounded	advanced	opening	mistake	Bxc6	b5c6	true	true	true	true	true	[]	2	true	[ { "sentence": "The student's mistake was not considering that the bishop on c6 is a strong attacking piece.", "reason": "no bishop on c6" }, { "sentence": "After Bxc6, the queen can target the c6 square, and the knight on f3 becomes a valuable piece.", "reason": "no knight on f3" } ]
2UticRp2_20	base	ungrounded	beginner	opening	blunder	Bxd2+	b4d2	true	true	false	true	true	[]	1	true	[ { "sentence": "After you play Bxd2+, the queen is now in a vulnerable position, and the knight is on c4, which is a weak square.", "reason": "no knight on c4" } ]
2UticRp2_20	base	grounded	beginner	opening	blunder	dxe5	d6e5	true	true	true	true	true	[]	0	false	[]
rKymuRxn_25	base	ungrounded	intermediate	middlegame	inaccuracy	e5	e4e5	true	true	false	true	true	[]	0	false	[]
rKymuRxn_25	base	grounded	intermediate	middlegame	inaccuracy	Qe2	d1e2	true	true	true	true	true	[]	0	false	[]
T997RAgX_53	base	ungrounded	advanced	middlegame	inaccuracy	Kf2	g1f2	true	true	true	true	true	[]	0	false	[]
T997RAgX_53	base	grounded	advanced	middlegame	inaccuracy	Kf2	g1f2	true	true	true	true	true	[]	0	false	[]
IeQpRCAn_44	base	ungrounded	beginner	endgame	inaccuracy	null	null	true	false	false	true	true	[]	0	false	[]
IeQpRCAn_44	base	grounded	beginner	endgame	inaccuracy	h5	h7h5	true	true	true	true	true	[]	0	false	[]
RZFnjp2S_65	base	ungrounded	intermediate	middlegame	mistake	Rxe7	c7e7	true	true	true	true	true	[]	1	true	[ { "sentence": "Your move Rxe7 was a good one, but it left your queen in a vulnerable position.", "reason": "White has no queen" } ]
RZFnjp2S_65	base	grounded	intermediate	middlegame	mistake	Rxe7	c7e7	true	true	true	true	true	[]	0	false	[]
Qyd4gSh6_23	base	ungrounded	advanced	opening	blunder	null	null	true	false	false	true	true	[]	0	false	[]
Qyd4gSh6_23	base	grounded	advanced	opening	blunder	Qxd4	d1d4	true	true	true	true	true	[]	0	false	[]
I72qKqM7_69	base	ungrounded	beginner	endgame	mistake	Ne6	d8e6	true	true	true	true	true	[]	0	false	[]
I72qKqM7_69	base	grounded	beginner	endgame	mistake	Ne6	d8e6	true	true	true	true	true	[]	0	false	[]
vnaJ19LZ_65	base	ungrounded	intermediate	endgame	inaccuracy	h4	h2h4	true	true	true	true	true	[]	0	false	[]
vnaJ19LZ_65	base	grounded	intermediate	endgame	inaccuracy	Rc8	c7c8	true	true	true	true	true	[]	0	false	[]
MqCso6fS_97	base	ungrounded	advanced	endgame	inaccuracy	bxa3	b2a3	true	true	true	true	true	[]	0	false	[]
MqCso6fS_97	base	grounded	advanced	endgame	inaccuracy	Kf5	g4f5	true	true	false	true	true	[]	0	false	[]
RahOyW25_105	base	ungrounded	beginner	endgame	blunder	Rg6	g5g6	true	true	false	true	true	[]	3	true	[ { "sentence": "The queen is already on d7, and the rook on g6 is not very strong.", "reason": "no rook on g6" }, { "sentence": "By playing Rd7, you're putting pressure on the black queen and preparing to support the queen's advancement.", "reason": "Black has no queen" }, { "sentence": "...
RahOyW25_105	base	grounded	beginner	endgame	blunder	Rh5+	g5h5	true	true	true	true	true	[]	0	false	[]
bWwdtmJb_18	base	ungrounded	intermediate	opening	inaccuracy	Bg4	c8g4	true	true	true	true	true	[]	0	false	[]
bWwdtmJb_18	base	grounded	intermediate	opening	inaccuracy	Bg4	c8g4	true	true	true	true	true	[]	0	false	[]
szINDRzX_104	base	ungrounded	advanced	endgame	mistake	null	null	true	false	false	true	true	[]	1	true	[ { "sentence": "Qb4 targets the opponent's queen and puts pressure on the center.", "reason": "White has no queen" } ]
szINDRzX_104	base	grounded	advanced	endgame	mistake	Bg7	h6g7	true	true	true	true	true	[]	0	false	[]
utEv6duM_17	base	ungrounded	beginner	opening	inaccuracy	Nf3	g1f3	true	true	false	true	true	[]	0	false	[]
utEv6duM_17	base	grounded	beginner	opening	inaccuracy	Qd3	c4d3	true	true	false	true	true	[]	2	true	[ { "sentence": "Now, after Bg5, the bishop is on g5, and the knight on f6 is under attack.", "reason": "no bishop on g5" }, { "sentence": "The next move could be Qd3, which both attacks the knight and prepares to take the pawn on e4.", "reason": "no pawn on e4" } ]
tdDp83CH_37	base	ungrounded	intermediate	middlegame	inaccuracy	Qc2	c1c2	true	true	false	true	true	[]	1	true	[ { "sentence": "However, you need to be careful with the bishop on c3.", "reason": "no bishop on c3" } ]
tdDp83CH_37	base	grounded	intermediate	middlegame	inaccuracy	Nf4	e2f4	true	true	true	true	true	[]	0	false	[]
S7XkYxxe_103	base	ungrounded	advanced	endgame	mistake	null	null	true	false	false	true	true	[]	0	false	[]
S7XkYxxe_103	base	grounded	advanced	endgame	mistake	Kd2	d3d2	true	true	true	true	true	[]	0	false	[]
QDJA7l6G_31	base	ungrounded	beginner	middlegame	mistake	Qe5	e4e5	true	true	false	true	true	[]	0	false	[]
QDJA7l6G_31	base	grounded	beginner	middlegame	mistake	h5	h4h5	true	true	true	true	true	[]	0	false	[]
bn1cOzcL_20	base	ungrounded	intermediate	opening	blunder	Nbc6	b8c6	true	true	false	true	true	[]	1	true	[ { "sentence": "After Nbc6, the queen is in a vulnerable position, and the bishop on g2 is a strong local threat.", "reason": "no bishop on g2" } ]
bn1cOzcL_20	base	grounded	intermediate	opening	blunder	Bxd2+	b4d2	true	true	false	true	true	[]	0	false	[]
diZkf8wa_37	base	ungrounded	advanced	middlegame	mistake	null	null	true	false	false	true	true	[]	0	false	[]
diZkf8wa_37	base	grounded	advanced	middlegame	mistake	c4	c2c4	true	true	true	true	true	[]	0	false	[]
Fr1dRrTh_21	base	ungrounded	beginner	opening	blunder	h4	h2h4	true	true	false	true	true	[]	0	false	[]
Fr1dRrTh_21	base	grounded	beginner	opening	blunder	Na4	c3a4	true	true	true	true	true	[]	0	false	[]
Em8mFeWp_35	base	ungrounded	intermediate	middlegame	mistake	fxe4	f3e4	true	true	true	true	true	[]	0	false	[]
Em8mFeWp_35	base	grounded	intermediate	middlegame	mistake	Qf4	d2f4	true	true	true	true	true	[]	0	false	[]
vWnrycED_27	base	ungrounded	advanced	middlegame	mistake	null	null	true	false	false	true	true	[]	0	false	[]
vWnrycED_27	base	grounded	advanced	middlegame	mistake	Bc4	f1c4	true	true	true	true	true	[]	0	false	[]
SJqFIdfn_21	base	ungrounded	beginner	opening	inaccuracy	Bc4	f1c4	true	true	false	true	true	[]	1	true	[ { "sentence": "After your move, the queen is now in a vulnerable position, and the pawn on d5 is weak.", "reason": "no pawn on d5" } ]
SJqFIdfn_21	base	grounded	beginner	opening	inaccuracy	Be2	f1e2	true	true	true	true	true	[]	0	false	[]
fxMOiONk_95	base	ungrounded	intermediate	endgame	inaccuracy	null	null	true	false	false	true	true	[]	0	false	[]
fxMOiONk_95	base	grounded	intermediate	endgame	inaccuracy	Rc7	h7c7	true	true	true	true	true	[]	0	false	[]
IOaMinH5_34	base	ungrounded	beginner	middlegame	inaccuracy	c5	c7c5	true	true	true	true	true	[]	0	false	[]
IOaMinH5_34	base	grounded	beginner	middlegame	inaccuracy	c5	c7c5	true	true	true	true	true	[]	0	false	[]
870dfTAs_88	base	ungrounded	intermediate	endgame	blunder	f3+	f4f3	true	true	true	true	true	[]	2	true	[ { "sentence": "After your move, the queen is now on b4, which is a strong threat to the king and also attacks the pawn on e5.", "reason": "no pawn on e5" }, { "sentence": "The knight on c4 is vulnerable, and the queen can follow up with a check or a forced win.", "reason": "no knight on c4" } ...
870dfTAs_88	base	grounded	intermediate	endgame	blunder	axb5	a6b5	true	true	true	true	true	[]	0	false	[]
uHDsJlF3_24	base	ungrounded	advanced	opening	mistake	Qb4+	d6b4	true	true	false	true	true	[]	2	true	[ { "sentence": "After your move, the queen is now in a vulnerable position, and the bishop is on c4, which is a good square to control the center.", "reason": "no bishop on c4" }, { "sentence": "The queen is now more active and can support the bishop on c4, which is a strong central piece.", "rea...
uHDsJlF3_24	base	grounded	advanced	opening	mistake	Bxg7	f8g7	true	true	true	true	true	[]	0	false	[]
YasRe9Rh_21	base	ungrounded	beginner	opening	blunder	null	null	true	false	false	true	true	[]	0	false	[]
YasRe9Rh_21	base	grounded	beginner	opening	blunder	Bg5	c1g5	true	true	true	true	true	[]	0	false	[]

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Chess coach benchmark

A comprehensive, zero-leakage benchmark measuring the performance of local chess-coaching fine-tunes against frontier models.

What it is

This benchmark evaluates models on held-out chess positions, measuring their ability to provide tier-calibrated, engine-grounded chess coaching. It scores models based on deterministic objective metrics (move soundness, absence of engine jargon, and verification of board facts) alongside a blinded, cross-family LLM council that assesses raw instructiveness.

How it was built

Step	Process
Positions	Held-out real Lichess positions (deduplicated by board placement and side to move) with zero leakage to the training set.
Grounding	Stockfish provides a sound pool of moves, and Maia provides tier-realistic human-move likelihoods. The grounded condition includes these verified facts in the prompt.
Generation	Models receive identical system prompts and format instructions to generate coaching outputs.
Objective scoring	Deterministic checks verify move soundness, lack of engine terminology, adherence to ply limits, and absence of fabricated board facts (via a non-LLM faithfulness verifier).
Council	A blinded panel (GPT-5.5, Claude Opus 4.8, Gemini 3.1 Pro) ranks anonymized outputs by instructiveness for the stated tier.

Tier-appropriate move behavior

A key part of the benchmark is measuring the tier fit. It evaluates whether the coach steers beginners toward human-findable moves and reserves sharp engine lines for advanced players. The benchmark explicitly checks the distribution of distinct moves across tiers for the same position.

Evaluation

Because evaluation numbers are actively regenerating through a grand eval, please refer to the live artifacts for the most current results (as of July 8, 2026):

Artifact	Link
Benchmark space	Live dashboard

Usage

You can download the dataset configurations to analyze the evaluation metrics and generations.

from datasets import load_dataset

ds = load_dataset("khoilamalphaai/chess-coach-benchmark", "objective_gap803")
print(ds["train"][0])

Links

Resource	Destination
Model	qwen3-1.7b-chess-coach-mlx
Dataset	chess-coach-move-review

Limitations

Limitation	Detail
Verifier strictness	The fabrication metric uses a conservative current-board verifier. Some flags may be legitimate forward-looking language, though this metric is applied identically across all models.
LLM-judge proxy	Instructiveness is measured by an LLM council, which serves as a proxy for human judgment. Blinded label files are provided for human re-labeling.