Chess puzzle (Checkmate)
Moves: 1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Be2 e5 7. Nb3 Be6 8. Be3
Be7 9. Qd2 O-O 10. O-O-O Nbd7 11. f3 b5 12. g4 Rc8 13. g5 Nh5 14. Nd5 Bxd5 15.
exd5 Nb6 16. h4 Nc4 17. Bxc4 bxc4 18. Na5 c3 19. bxc3 Qxa5 20. Kb2 Rc4 21. Qd3
Rb8+ 22. Ka1 Qxa2+ 23. Kxa2 *
Position (FEN): 1r4k1/4bppp/p2p4/3Pp1Pn/2r4P/2PQBP2/K1P5/3R3R b - - 0 23
Black to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 1020
Best move: Ra4#