

What do you think the overlap is in two groups of outliers?
Well, seeing as people with abnormal sex genes may have an advantage in competitive women’s sports, you would actually expect to see a significant amount of that “outlier” group in the group of top athletes, as there is a selection happening. You’re right that if you chose independently at random from people who are top athletes and people who have abnormal sex genes, the overlap would be incredibly small. But sports is not a random selection at all. At the top of sports, even the smallest advantage means the difference between winning and losing, so even small variations (like those caused by abnormal sex genes) may give significant advantages (perhaps even “unfair” advantages).
That is, in theory. In practice, it can make a big difference. Source: Worked professionally with large services built in Python and Rust.