Chess puzzle (Checkmate)
Opening: Philidor_Defense, Philidor_Defense_Exchange_Variation
Moves: 1. e4 e5 2. Nf3 d6 3. d4 exd4 4. Nxd4 h6 5. Nc3 Nf6 6. Bd2 Be7 7. Qf3 O-O 8.
O-O-O a5 9. Nde2 c6 10. Ng3 b5 11. Nce2 b4 12. Nh5 Bb7 13. Nxf6+ Bxf6 14. Qg3
Kh8 15. Nf4 c5 16. Nh5 a4 17. Nxf6 Qxf6 18. a3 bxa3 19. bxa3 *
Position (FEN): rn3r1k/1b3pp1/3p1q1p/2p5/p3P3/P5Q1/2PB1PPP/2KR1B1R b - - 0 19
Black to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 1278
Best move: Qa1#