Chess puzzle (Advantage)
Opening: Queens_Pawn_Game, Queens_Pawn_Game_Mason_Attack
Moves: 1. f4 d5 2. d4 e6 3. Nc3 c5 4. e4 c4 5. e5 Nc6 6. Nf3 a6 7. Be3 h6 8. b3 b5 9.
a4 Bd7 10. Be2 Qa5 11. Bd2 Bb4 *
Position (FEN): r3k1nr/3b1pp1/p1n1p2p/qp1pP3/PbpP1P2/1PN2N2/2PBB1PP/R2QK2R w KQkq - 5 12
White to move.
Themes:  Middlegame  
Puzzle rating: 1629
Best move: axb5