Chess puzzle (Checkmate)
Opening: English_Defense, English_Defense_Other_variations
Moves: 1. d4 b6 2. Bg5 Bb7 3. Nf3 g6 4. e3 Bg7 5. c3 d5 6. Nbd2 Nd7 7. Be2 h6 8. Bh4
g5 9. Bg3 e6 10. h4 Bf6 11. hxg5 Bxg5 12. Nxg5 Qxg5 13. O-O O-O-O 14. c4 h5 15.
cxd5 Bxd5 16. Qc2 c5 17. Ba6+ Bb7 18. Qc4 Bxa6 *
Position (FEN): 2kr2nr/p2n1p2/bp2p3/2p3qp/2QP4/4P1B1/PP1N1PP1/R4RK1 w - - 0 19
White to move.
Themes: Queenside Attack Middlegame Mate in 1 
Puzzle rating: 525
Best move: Qxa6#