Chess puzzle (Checkmate)
Moves: 1. d4 d6 2. Nf3 Bg4 3. c4 Nd7 4. Qb3 Ngf6 5. h3 Bf5 6. Nc3 e5 7. Qxb7 Rb8 8.
Qxa7 e4 9. Nh4 Bg6 10. Nxg6 hxg6 11. Qa4 e3 12. Bxe3 Rxb2 13. g4 Nxg4 14. O-O-O
Nxe3 15. fxe3 Qb8 16. Nb5 Nb6 17. Qa6 Nxc4 18. Bg2 Rh5 19. Bc6+ Kd8 20. Nc3
Rb1+ 21. Nxb1 *
Position (FEN): 1q1k1b2/2p2pp1/Q1Bp2p1/7r/2nP4/4P2P/P3P3/1NKR3R b - - 0 21
Black to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 1174
Best move: Qb2#