Dear track and field athletes: Hope you like needles, because we're going to test your testosterone levels before every competition and enter you into the appropriate category the day of your race. Sure this will cost us millions and millions of dollars but since you all want things fair and fair seems to be based on the level of testosterone these days based on responses to Caster Semenya's latest race win, let's just do it.
It will be exciting, right? For us: we'll get to watch multiple race finals instead of just one. I mean you'll have no idea who your competition is until the race. You'll have no idea which category you'll be in until that race. This testing system will not only take care of people "on the very fringe of the normal athlete female biological composition" but those who get advantages from being at certain points in their menstrual cycle. And we won't have those silly labels like "fastest woman in the world"; we can just go with "fastest human with T level ____."
So raise your hand if you want fairness. And while it's up there we'll just draw a small amount of blood so we can see just how fringe you are or are not.