Chess puzzle (Checkmate)
Moves: 1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. O-O Nf6 5. Re1 Ng4 6. Rf1 O-O 7. c3 d6 8. d4
exd4 9. cxd4 Bb6 10. Bg5 Qe8 11. d5 Nce5 12. Be2 f6 13. Bh4 Ng6 14. Bg3 Qxe4
15. Nc3 Qe8 16. Re1 N4e5 17. Rc1 Bg4 18. Nxe5 Bxe2 19. Nxg6 Bxd1 20. Rxe8 Raxe8
21. Nxf8 *
Position (FEN): 4rNk1/ppp3pp/1b1p1p2/3P4/8/2N3B1/PP3PPP/2Rb2K1 b - - 0 21
Black to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 827
Best move: Re1#