Chess puzzle (Checkmate)
Moves: 1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 g6 5. Nc3 Bg7 6. Be3 Nf6 7. f3 O-O 8.
Qd2 d6 9. O-O-O a6 10. Bc4 Ne5 11. Bb3 b5 12. g4 Bd7 13. h4 a5 14. a3 b4 15.
Nd5 bxa3 16. bxa3 Nxd5 17. Bxd5 Rc8 18. h5 Qb6 19. Nc6 Nxf3 20. Nxe7+ Kh8 21.
hxg6 *
Position (FEN): 2r2r1k/3bNpbp/1q1p2P1/p2B4/4P1P1/P3Bn2/2PQ4/2KR3R b - - 0 21
Black to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 1518
Best move: Qb2#