Chess puzzle (Checkmate)
Opening: Blackmar-Diemer_Gambit, Blackmar-Diemer_Gambit_Netherlands_Variation
Moves: 1. d4 d5 2. e4 dxe4 3. Nc3 f5 4. f3 exf3 5. Qxf3 Nf6 6. Bg5 Qxd4 7. Be3 Qh4+ 8.
g3 Qg4 9. Qf2 Nc6 10. Be2 Qb4 11. O-O-O Bd7 12. Nb5 Qa5 13. a3 a6 14. Nd4 O-O-O
15. Nxc6 bxc6 16. Bd2 e6 17. Qa7 Qb6 18. Qa8+ Qb8 *
Position (FEN): Qqkr1b1r/2pb2pp/p1p1pn2/5p2/8/P5P1/1PPBB2P/2KR2NR w - - 4 19
White to move.
Themes: Queenside Attack Opening Mate in 1 
Puzzle rating: 1113
Best move: Bxa6#