Petrov's Defense: Classical, Nimzowitsch Attack

1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.Nc3 Nxc3 6.dxc3 Be7 7.Be3 O-O 8.Qd2 Nd7 9.O-O-O