It is often difficult for White to prove an advantage in symmetrical opening lines . As GM Bent Larsen wrote , annotating a game that began 1.c4 c5 2.b3 b6 , " In symmetrical openings , White have a theoretical advantage , but in many of them it is only theoretical . " GM Andrew Soltis wrote in 2008 that he hate playing against the symmetrical Petroff 's Defense ( 1.e4 e5 2.Nf3 Nf6 ) , and accordingly vary with 2.Nc3 , the Vienna Game . However , there too he have been unable to find a way to an advantage after the symmetrical 2 ... Nc6 3.g3 g6 4.Bg2 Bg7 , or after 3.Nf3 Nf6 ( transposing to the Four Knights Game ) 4.Bb5 Bb4 5 @.@ 0 @-@ 0 0 @-@ 0 6.d3 d6 7.Bg5 Bg4 8.Nd5 Nd4 9.Nxb4 Nxb5 , or 7.Ne2 Ne7 8.c3 Ba5 9.Ng3 c6 10.Ba4 Ng6 11.d4 d5 , when 12.exd5 ? ! e4 ! may even favor Black .