Originally Posted by OBoile

As for the science itself, until recently, no major studies had been done on the matter, so there was only speculation. Sort of like > 100 years ago when CO2 was proposed as a greenhouse gas but there wasn't massive amounts of data to back it up like there is today. Now we are starting to get some research on the effects of hormone suppression but even those results don't directly deal with performance.

In short, while people can speculate about certain factors which could cause an unfair advantage for trans women, no one really knows how much of a benefit, if any, that they receive overall in a particular sport.