Semi-Slav Defense: Main Line, Ståhlberg Variation

1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Bd3 dxc4 7.Bxc4 b5 8.Bd3 a6 9.e4 c5 10.e5 cxd4 11.Nxb5 Nxe5 12.Nxe5 axb5 13.Qf3