As this related Freakonomics blog post notes:
Using data from the 2010 World Series of Poker, Levitt and Miles found that high-skilled players earned an average return on investment of over 30 percent, whereas all other players averaged a 15 percent loss. This finding has serious implications on the legality of online poker, as that debate is heavily dependent on whether the game is based on skill or luck.Also noteworthy:
The differences are "far larger in magnitude than those observed in financial markets, where fees charged by the money managers viewed as being most talented can run as high as 3 percent of assets under management and 30 percent of annual returns."
