Chess puzzle (Checkmate)
Moves: 1. d4 d5 2. Nf3 Nf6 3. c4 e6 4. Bg5 Be7 5. Nc3 O-O 6. e3 h6 7. Bh4 Nbd7 8. Rc1
a6 9. c5 c6 10. Be2 b5 11. b4 a5 12. a3 axb4 13. axb4 Bb7 14. O-O Ra3 15. Nd2
Qa8 16. Nb3 Bd8 17. Bf3 e5 18. Ra1 exd4 19. exd4 Re8 20. Qc2 Rxa1 21. Rxa1
Qxa1+ 22. Nxa1 *
Position (FEN): 3br1k1/1b1n1pp1/2p2n1p/1pPp4/1P1P3B/2N2B2/2Q2PPP/N5K1 b - - 0 22
Black to move.
Themes:  Middlegame Back Rank Mate, Mate in 1 
Puzzle rating: 748
Best move: Re1#