Chess puzzle (Checkmate)
Moves: 1. e4 e5 2. Nf3 Bc5 3. Bc4 c6 4. O-O d6 5. c3 h6 6. h3 Nf6 7. Re1 O-O 8. d4
exd4 9. cxd4 Bb4 10. Nc3 Bxc3 11. bxc3 Re8 12. e5 dxe5 13. Nxe5 Nd5 14. Qf3 Qf6
15. Qg3 b5 16. Bb3 a5 17. Bb2 a4 18. Bc2 a3 19. Nxc6 Rxe1+ 20. Rxe1 Nxc6 *
Position (FEN): r1b3k1/5pp1/2n2q1p/1p1n4/3P4/p1P3QP/PBB2PP1/4R1K1 w - - 0 21
White to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 817
Best move: Re8#