Chess puzzle (Checkmate)
Moves: 1. e4 e5 2. Bc4 Nf6 3. d3 Bc5 4. Nc3 d6 5. f4 exf4 6. Bxf4 Ng4 7. Nh3 Qf6 8.
Nd5 Qd8 9. Qf3 c6 10. Bg5 f6 11. Nxf6+ Nxf6 12. Rf1 Bg4 13. Bxf6 Bxf3 14. Bxd8
Bxg2 15. Rg1 Bxh3 16. Rxg7 Kxd8 17. O-O-O Nd7 18. Rdg1 Bxg1 19. Rxg1 Ne5 20.
Bg8 Kc7 21. Rg7+ Kb6 22. d4 Nf3 23. Bc4 Nxd4 24. c3 Nb5 25. a4 Nc7 26. b4 d5 *
Position (FEN): r6r/ppn3Rp/1kp5/3p4/PPB1P3/2P4b/7P/2K5 w - - 0 27
White to move.
Themes:  Endgame Mate in 1 
Puzzle rating: 1015
Best move: a5#