From a science standpoint it's not that easy. We used to use XX XY testing in the Olympics until we found out that some XY don't turn on that Y and develop like a female and now we know that some XX develop as males and this does not even cover the XXY folks!
And to make this so much worse, for those who like it binary, there is a group of protists that have 13 different mating types with very strange rules concerning which pair can exchange DNA. Just when it looked so easy...The Olympics still uses a "hybrid " method. Does Spurter wanna pay for it? Involves DNA, hormone levels, and physical examination.
Spurter, you take the physical exam part, I wanna no part o dat.
The good ole days when Russian(and East German) men were women is gone, in the Olympics anyways. But Texas... yes.