Chess puzzle (Checkmate)
Moves: 1. e4 c5 2. Nf3 Nf6 3. Nc3 e6 4. d4 cxd4 5. Nxd4 Nc6 6. Be3 a6 7. f3 Be7 8. Qd2
O-O 9. O-O-O b5 10. a3 Bb7 11. g4 b4 12. axb4 Nxb4 13. g5 Nh5 14. f4 Rc8 15.
Be2 Rxc3 16. bxc3 Qa5 17. Nb3 Qa3+ 18. Kb1 Qa2+ 19. Kc1 Nd5 20. exd5 *
Position (FEN): 5rk1/1b1pbppp/p3p3/3P2Pn/5P2/1NP1B3/q1PQB2P/2KR3R b - - 0 20
Black to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 1236
Best move: Ba3#