How many students would you say per high school or college/university do you think are in the closet and on their school's team sport(s)?

I honestly have no idea at all. But I see no reason why it would substantially different than the % of gay men in the population as a whole. That number, of course, is hotly debated. Off the cuff, I'd say that at a minimum, an average of one per team is certainly not unreasonable (depending on team size, naturally).

I would have to say that high school may not be so easy to measure in that many folks are still figuring out their sexual identities.

All of them!

No seriously, Tiger's analysis is probably right on.

Only in my crazier (and very fun ) fantasies!

A'ight! Glad to see ya laugh!