Chess puzzle (Advantage)
Opening: Queens_Gambit_Declined, Queens_Gambit_Declined_Vienna_Variation
Moves: 1. d4 e6 2. c4 d5 3. Nc3 Nf6 4. Nf3 dxc4 5. e4 c5 6. d5 exd5 7. exd5 Be7 8.
Bxc4 O-O 9. O-O a6 10. a4 Nbd7 *
Position (FEN): r1bq1rk1/1p1nbppp/p4n2/2pP4/P1B5/2N2N2/1P3PPP/R1BQ1RK1 w - - 1 11
White to move.
Themes:  Opening  
Puzzle rating: 1234
Best move: d6