Chess puzzle (Advantage)
Opening: French_Defense, French_Defense_Knight_Variation
Moves: 1. Nf3 e6 2. e4 d5 3. exd5 exd5 4. d4 Bf5 5. Bf4 Nf6 6. Bd3 Bxd3 7. Qxd3 c6 8.
Nc3 Be7 9. O-O-O b5 10. Rde1 O-O 11. Kb1 a5 12. a3 b4 13. axb4 *
Position (FEN): rn1q1rk1/4bppp/2p2n2/p2p4/1P1P1B2/2NQ1N2/1PP2PPP/1K2R2R b - - 0 13
Black to move.
Themes:  Middlegame  
Puzzle rating: 1480
Best move: axb4