Chess puzzle (Checkmate)
Opening: Ruy_Lopez, Ruy_Lopez_Steinitz_Defense
Moves: 1. e4 e5 2. Nf3 Nc6 3. Bb5 d6 4. O-O Bd7 5. d4 exd4 6. Nxd4 Ne5 7. Bxd7+ Qxd7
8. f4 Nc6 9. Kh1 O-O-O 10. Na3 Nf6 11. Qd3 d5 12. e5 Ne4 13. Nab5 Bc5 14. Be3
a6 15. Nxc6 bxc6 16. Na7+ Bxa7 17. Bxa7 c5 *
Position (FEN): 2kr3r/B1pq1ppp/p7/2ppP3/4nP2/3Q4/PPP3PP/R4R1K w - - 0 18
White to move.
Themes: Queenside Attack Middlegame Mate in 1 
Puzzle rating: 444
Best move: Qxa6#