Chess puzzle (Checkmate)
Moves: 1. e4 e5 2. Nf3 Nc6 3. d4 Nxd4 4. Nxd4 exd4 5. Qxd4 d6 6. Nc3 c5 7. Qd5 Nf6 8.
Qc4 Be6 9. Qb5+ Bd7 10. Qxb7 Be7 11. Nd5 Nxd5 12. Qxd5 O-O 13. Be3 Be6 14. Qd3
Qb6 15. b3 Bf6 16. O-O-O Rac8 17. Qxd6 Qa5 18. a4 Qc3 19. Bd3 Bxb3 20. Bd2 *
Position (FEN): 2r2rk1/p4ppp/3Q1b2/2p5/P3P3/1bqB4/2PB1PPP/2KR3R b - - 1 20
Black to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 866
Best move: Qa1#