Chess puzzle (Checkmate)
Moves: 1. e4 e5 2. Nf3 Nf6 3. Nc3 d6 4. d4 exd4 5. Nxd4 Be6 6. Bg5 Be7 7. Bd3 O-O 8.
O-O h6 9. Bh4 Nh7 10. Bxe7 Qxe7 11. Re1 c5 12. Nf3 Nc6 13. Nd5 Qd7 14. c3 Bg4
15. h3 Bxf3 16. Qxf3 Ne5 17. Qd1 Nxd3 18. Qxd3 b5 19. b3 a5 20. Red1 Rad8 21.
a4 b4 22. Nb6 Qe6 23. Nc4 bxc3 24. Rac1 Nf6 25. f3 d5 26. exd5 Rxd5 27. Qxc3
Rxd1+ 28. Rxd1 Nd5 29. Qe1 Qxe1+ 30. Rxe1 Ra8 31. Re5 Nb4 32. Rxc5 Nd3 33. Rxa5
Re8 34. Rd5 Re1+ 35. Kh2 Nf4 36. Rb5 Re2 37. Kg3 Nxg2 38. a5 g5 39. a6 Nf4 40.
a7 *
Position (FEN): 6k1/P4p2/7p/1R4p1/2N2n2/1P3PKP/4r3/8 b - - 0 40
Black to move.
Themes:  Endgame Hook Mate, Mate in 1 
Puzzle rating: 820
Best move: Rg2#