Chess puzzle (Checkmate)
Opening: Sicilian_Defense, Sicilian_Defense_Alapin_Variation
Moves: 1. e4 c5 2. c3 d6 3. d4 Nc6 4. dxc5 dxc5 5. Qxd8+ Kxd8 6. Bf4 e5 7. Bg3 Be6 8.
Na3 a6 9. O-O-O+ Kc7 10. Nc4 f6 11. f4 exf4 12. Bxf4+ Kc8 *
Position (FEN): r1k2bnr/1p4pp/p1n1bp2/2p5/2N1PB2/2P5/PP4PP/2KR1BNR w - - 1 13
White to move.
Themes:  Opening Mate in 1 
Puzzle rating: 1293
Best move: Nb6#