Semi-Slav Defense: Main Line, Stoltz Variation

1.d4 d5 2.c4 c6 3.Nc3 Nf6 4.e3 e6 5.Nf3 Nbd7 6.Qc2 Bd6 7.Bd3 dxc4 8.Bxc4 b5 9.Bd3 Bb7 10.O-O O-O 11.a3 a5