So is developing male. That's most of the point of having separate contests for men and women.

And transition is not known to have adequate effects to restore fairness, which is why I phrased my question (two replies ago) the way I did. Even the very pro-trans-sport article you linked had to admit as much, because they were, to their credit, reasonably fair when it came to presenting the data, and the data is quite lacking compared to what is really needed.

We can argue that the construal of fairness in sport is weird--overly fixated on what is "natural" and fanatic about policing those potentially performance-enhancing deviations that have been declared unnatural, while being indifferent to the much larger advantages and disadvantages people have due to their biology. So if you were to argue that the ideal of fairness needs a revamp, well, sure, have a go.

You could try to argue, as you sort of are now, that the fair thing to do is assume the material effects are adequate (even though the data is insufficient to support that), lift any bans, and then institute them again if, when better data comes in, it's shown to be unfair--but if you're going to argue this way, you had better take full account of the permanent cloud over cycling records and over, say, Major League Baseball home run records in the U.S., because looking back on that pretty much everyone involved thinks it sucks that every record is contaminated.

But the position that there are no concerns about fairness as currently construed is completely unsupportable.

And the slippery slope argument ("tomorrrow...god only knows what else") goes exactly the other way: if the standard approach is to attack people who have legitimate concerns about the potential to change the rules of the game by saying they exhibit "deeply harmful prejudice", the consequence is to push them down the slope.

After having lost credibility on the issue of sports, why would people be inclined to listen about bathrooms? Of course it's a logical fallacy not to listen the new set of arguments, but why tempt people into committing the fallacy unless you care more about setting them up for a "gotcha!" in an argument than about the actual conditions that entail?

If you're worried about "god only knows what else", the better strategy is to take the easy victories and solidify them. "Children should stay with loving parents" should be a no-brainer especially when talking to people who claim they dislike government intervention.