Chess puzzle (Checkmate)
Moves: 1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 a6 5. Nc3 e6 6. Be3 Be7 7. Bc4 Na5 8.
Bd3 b5 9. a3 Bb7 10. Qg4 g5 11. h4 h5 12. Qg3 g4 13. O-O-O b4 14. axb4 Bxb4 15.
Nb1 Rc8 16. f3 Ne7 17. Bg5 gxf3 18. Qxf3 Qb6 19. Be3 Qxd4 20. Bxd4 *
Position (FEN): 2r1k2r/1b1pnp2/p3p3/n6p/1b1BP2P/3B1Q2/1PP3P1/1NKR3R b k - 0 20
Black to move.
Themes: Pin Middlegame Mate in 1 
Puzzle rating: 1077
Best move: Nb3#