Chess puzzle (Checkmate)
Moves: 1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. d3 Nf6 5. O-O a6 6. h3 d6 7. a3 h6 8. Nc3 g5
9. Nd5 g4 10. Nxf6+ Qxf6 11. hxg4 Bxg4 12. Be3 Rg8 13. Kh1 Nd4 14. Bxd4 Bxd4
15. c3 Bb6 16. Bd5 O-O-O 17. b4 Rg5 18. b5 Bxf3 19. Qxf3 Qxf3 20. gxf3 Rh5+ 21.
Kg2 *
Position (FEN): 2kr4/1pp2p2/pb1p3p/1P1Bp2r/4P3/P1PP1P2/5PK1/R4R2 b - - 2 21
Black to move.
Themes:  Endgame Mate in 1 
Puzzle rating: 1458
Best move: Rg8#