Chess puzzle (Checkmate)
Moves: 1. Nf3 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. d4 O-O 6. Be2 Nc6 7. O-O e5 8. d5
Ne7 9. Ne1 c6 10. f3 b5 11. dxc6 bxc4 12. Bxc4 Qb6+ 13. Kh1 Nxc6 14. Qxd6 Rd8
15. Qa3 Na5 16. Bd5 Bf8 17. Qa4 Ba6 18. Bxa8 Bxf1 19. Bd5 Qf2 20. Qxa5 Bxg2+
21. Nxg2 *
Position (FEN): 3r1bk1/p4p1p/5np1/Q2Bp3/4P3/2N2P2/PP3qNP/R1B4K b - - 0 21
Black to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 1367
Best move: Qf1#