Chess puzzle (Checkmate)
Opening: Sicilian_Defense, Sicilian_Defense_Delayed_Alapin
Moves: 1. e4 c5 2. Nf3 d6 3. c3 Nc6 4. d4 cxd4 5. cxd4 Nf6 6. Bd3 g6 7. Be3 Bg7 8. Nc3
Bg4 9. Be2 O-O 10. Qd2 Rc8 11. O-O-O Qa5 12. h3 Bxf3 13. Bxf3 Nb4 14. Kb1 Nd7
15. Nd5 *
Position (FEN): 2r2rk1/pp1nppbp/3p2p1/q2N4/1n1PP3/4BB1P/PP1Q1PP1/1K1R3R b - - 4 15
Black to move.
Themes: Queenside Attack Middlegame Mate in 1 
Puzzle rating: 831
Best move: Qxa2#