Chess puzzle (Advantage)
Moves: 1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Be3 e5 7. Nb3 Be6 8. f3
Be7 9. Qd2 O-O 10. Be2 b5 11. O-O-O Nbd7 12. Kb1 b4 13. Nd5 Bxd5 14. exd5 a5
15. g4 a4 16. Nc1 b3 17. cxb3 axb3 18. Nxb3 Qb8 19. h4 Nc5 20. h5 *
Position (FEN): rq3rk1/4bppp/3p1n2/2nPp2P/6P1/1N2BP2/PP1QB3/1K1R3R b - - 0 20
Black to move.
Themes:  Middlegame  
Puzzle rating: 1174
Best move: Nxb3