Similarly, if you put me heads-up against a poker pro, I might stand as much as a 10% chance of knocking them out (by getting lucky on the river on an all-in)
In this case, you can probably improve your chances by making the game more about luck -- just go all-in every hand.
Gil Kalai, a well known mathematician, has this to say on the topic of chess and luck:
http://gilkalai.wordpress.com/2009/07/05/chess-can-be-a-game-of-luck/
I didn't follow his argument at all, but it seems like something other LW posters may understand, so I decided to post it here. Do comment on his arguments if you agree or disagree with him.