Chess puzzle (Checkmate)
Moves: 1. f4 d5 2. e3 c5 3. Nf3 Nc6 4. Be2 e6 5. O-O Nf6 6. b3 Bd6 7. Bb2 b6 8. Ne5
Bxe5 9. fxe5 Nd7 10. d4 cxd4 11. exd4 O-O 12. Bh5 Ba6 13. Rf2 Qg5 14. Bc1 Qh4
15. c3 f6 16. Rf4 Qg5 17. Rxf6 Qh4 18. Rxe6 Qf2+ 19. Kh1 Qf1+ 20. Qxf1 *
Position (FEN): r4rk1/p2n2pp/bpn1R3/3pP2B/3P4/1PP5/P5PP/RNB2Q1K b - - 0 20
Black to move.
Themes:  Middlegame Back Rank Mate, Mate in 1 
Puzzle rating: 778
Best move: Rxf1#