Chess puzzle (Advantage)
Opening: Sicilian_Defense, Sicilian_Defense_Najdorf_Variation
Moves: 1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Be3 e5 7. Nb3 Be7 8. Qd2
O-O 9. f3 Be6 10. O-O-O Nbd7 11. Kb1 Rc8 12. Be2 b5 13. Bxb5 *
Position (FEN): 2rq1rk1/3nbppp/p2pbn2/1B2p3/4P3/1NN1BP2/PPPQ2PP/1K1R3R b - - 0 13
Black to move.
Themes:  Middlegame  
Puzzle rating: 1491
Best move: axb5