Chess puzzle (Advantage)
Opening: Queens_Gambit_Declined, Queens_Gambit_Declined_Marshall_Defense
Moves: 1. d4 Nf6 2. c4 d5 3. cxd5 Nxd5 4. e4 Nf6 5. Nc3 e6 6. Nf3 Be7 7. Bc4 O-O 8.
O-O c6 9. Re1 a5 10. Bg5 a4 11. Nxa4 *
Position (FEN): rnbq1rk1/1p2bppp/2p1pn2/6B1/N1BPP3/5N2/PP3PPP/R2QR1K1 b - - 0 11
Black to move.
Themes:  Opening  
Puzzle rating: 1624
Best move: b5