Chess puzzle (Checkmate)
Moves: 1. e4 e5 2. Nf3 Nc6 3. Bc4 h6 4. d4 exd4 5. Nxd4 Be7 6. O-O Ne5 7. Bb3 Nf6 8.
Nc3 O-O 9. f4 Nc6 10. e5 Nxd4 11. Qxd4 Ne8 12. Nd5 d6 13. Nxe7+ Qxe7 14. Bd2
Be6 15. Rae1 dxe5 16. Rxe5 Qd6 17. Qe3 Bxb3 18. axb3 Nf6 19. Bc3 Ng4 20. Qg3
Nxe5 21. Bxe5 Qb6+ 22. Kh1 Qg6 23. Qc3 c6 24. Rf3 f6 25. Rg3 Qe4 26. Bxf6 Rxf6
27. Qxf6 *
Position (FEN): r5k1/pp4p1/2p2Q1p/8/4qP2/1P4R1/1PP3PP/7K b - - 0 27
Black to move.
Themes:  Endgame Back Rank Mate, Mate in 1 
Puzzle rating: 647
Best move: Qe1#