Chess puzzle (Checkmate)
Moves: 1. d4 Nf6 2. c3 e6 3. Nf3 d5 4. Bg5 Be7 5. e3 O-O 6. Bd3 c5 7. Ne5 Nc6 8. f4
Ne4 9. Bxe7 Qxe7 10. Bxe4 dxe4 11. O-O Nxe5 12. fxe5 b6 13. Nd2 Bb7 14. Rf4 f5
15. exf6 Rxf6 16. Qg4 Raf8 17. Raf1 Ba6 18. R1f2 e5 19. Rxf6 Rxf6 20. Rxf6 Qxf6
21. Nxe4 *
Position (FEN): 6k1/p5pp/bp3q2/2p1p3/3PN1Q1/2P1P3/PP4PP/6K1 b - - 0 21
Black to move.
Themes:  Endgame Mate in 1 
Puzzle rating: 786
Best move: Qf1#