I didn’t realize that....what prompted the discussion was when Brittany Griner(sp?) from Baylor dropped out of the Olympic Team...there were some rumors she was a guy.
How do you decide whether someone's a woman?
A month before the 2012 London Olympic Games the IOC announced that the ability to compete as a woman will would be defined by chromosomes, DNA or genitals but by androgen levels.
Here's a decent ESPN story about gender identity and sports. Complete Androgen Insensitivity Syndrome, ambiguous genitals, internal sex organs that don't match external ones, an extra chromosome such as men with an XXY combination, and more.