Chess puzzle (Checkmate)
Moves: 1. e4 c5 2. d4 cxd4 3. Qxd4 Nc6 4. Qd1 Nf6 5. Nc3 e5 6. Bg5 Bb4 7. Qf3 h6 8.
Bh4 Nd4 9. Qd3 b6 10. Nf3 Nxf3+ 11. Qxf3 Bb7 12. O-O-O Rc8 13. Bb5 a6 14. Rxd7
Nxd7 15. Bxd8 Rxd8 16. Bc4 O-O 17. Nd5 b5 18. Bxb5 Bxd5 19. Bxd7 Bxa2 20. Ba4
Rd4 21. b3 *
Position (FEN): 5rk1/5pp1/p6p/4p3/Bb1rP3/1P3Q2/b1P2PPP/2K4R b - - 0 21
Black to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 1467
Best move: Ba3#