Chess puzzle (Advantage)
Opening: Queens_Pawn_Game, Queens_Pawn_Game_Veresov_Attack
Moves: 1. d4 d5 2. Nc3 Nf6 3. Nf3 e6 4. Bg5 Be7 5. e3 c5 6. dxc5 O-O 7. Bd3 h6 8. Bxf6
Bxf6 9. Qd2 Nd7 10. b4 a5 11. b5 Nxc5 12. Rb1 Ra6 *
Position (FEN): 2bq1rk1/1p3pp1/r3pb1p/pPnp4/8/2NBPN2/P1PQ1PPP/1R2K2R w K - 2 13
White to move.
Themes:  Middlegame  
Puzzle rating: 1126
Best move: bxa6