You've got a good point lefty. Lefties will be over represented in sports where coaches want a balance of left to right handers, like soccer, baseball and cricket (this explains why all soccer left backs are crap).
However in sports where leftiness provides no real advantage, like golf, tennis or rugby (maybe), the numbers are more representative.
Apparently more left-footed soccer players are "one-footed" because coaches don't have them practice using their right, whereas for a right-footed player, the ability to use both feet is considered a big advantage.
You can easily distinguish left-footed runners, they're the ones racing clockwise around the track.