I think Olympian256 is right. I believe symmetrical positions *will* tend to let you hold on longer, similar to the nature of d-pawn openings. Symmetrical positions remind me of two football players pushing against each other while standing on ice. While there are no unexpected dangers lurking around the bend because everything is so clearly visible, all it takes is one slip to let the other guy get an advantage where he just keeps on pushing and you just keep on sliding. It's easy to make that slip: all it takes is for White to make a pointless move like an unprovoked h3 to allow Black to get the initiative.
I like symmetrical positions as White or Black. I like them as White because Black must know the opening, sometimes out to 10-12 moves, to know when it suddenly becomes a mistake to continue the symmetry. In the case of Petroff's Defense, that point is reached at the 3rd-4th move; in certain variations of the Four Knights Game, that point can be reached at about the 10th-12th move. I'm mostly relying on book knowledge to win in such cases, hoping that Black doesn't know book, and that I'll know how to exploit his mistake. I'm also relying on having the initiative, though that isn't a very big advantage, especially as the game reaches the early middlegame. I also like symmetrical positions as Black, partly because White sometimes gets scared and starts playing defensively with suboptimal moves, whereupon I get an advantage, and partly because symmetrical positions have a *tendency* to lead to draws, meaning there is more leeway for error than in sharp, tactical domains.
Hi.
Do you have any tips about playing in symetrical positions.
For example.If i was black and playing a gm this what i would think"He has the same position as me just with a tempo more my only chande of wining is he makes a big mistake"