That is known. That is also why you typically do sex segregation only from 14-15 onward or start even later. There is no reason to do so until boys and girls on average give significantly different result.
If girls at 12-13 are, on average, bigger and stronger than boys due to earlier puberty, then why is it fair for them to compete with boys? Is that not terribly unfair on the boys?
As easy as it is to retroactively concoct reasons why children's sports are segregated, in reality it has very little, if anything to do with physical ability, at least not until the kids are basically adults. Most of the time, boys and girls will be encouraged to play completely different sports because of weird ideas about the relative manliness or otherwise of particular kinds of sport. Other times, they are segregated because of the fear that they might accidentally touch each other and develop unchristian thoughts.
And ultimately, that's the motivation here too. That's why you have this law that is not worded to be based on any kind of judgement or disctintion that would actually make sense. Like, I know we didn't touch on puberty blockers but let's do it now, an AMAB transwoman on puberty blockers is, on average, going to be smaller and weaker than a cis woman of the same age because puberty blockers (prepare to have your mind blown) suppress the symptoms of puberty. Do you believe that the mere act of possessing a dick will give her a physical advantage over cis women despite being quantifiably less physically developed than them?
It does not actually matter what your assigned sex was at birth, the only thing that could arguably matter is what is going on in your body in the present. The assholes could have written a law based on that (and it would have been a hilarious mess) but they didn't, because they don't actually care. That's not the point.
But no, you have girl teams and girl competitions precisely because you don't want girls to lose any interest in the sport because they now they could never compete with the boys anyway.
Isn't that what happens anyway?
Your entire argument for segregation is that girls could never compete with the boys (ironically at the one point in their lives when they actually could). In a world where men's sports receives overwhelmingly better funding, better representation and better societal interest, is it really surprising that girls lose interest in sports? Segregated competitions are essentially confining girls to a secondary role in athletics where their achievements will be continuously overlooked and devalued relative to those of boys.
b) If the blockers do put a trans-girl in the typical testosterone range for a girl of her age, and a doctor signs a note as such, that qualifies in this bill.
a) The bill specifically states that an athlete must prove they were assigned female at birth.
b) The "typical testosterone range" for a healthy teenage girl can be higher than that of many boys of the same age. Again, the bodies of adolescents are different from those of adults.
c) A significant number of women, for various reasons will not fall into the "typical testosterone range". There are very common medical conditions which can affect the hormone balance in the body of a woman or girl who was nonetheless assigned female at birth.
Again, this is just more evidence that the bill was written and supported by people who either lacked even the most basic, 5 seconds on wikipedia understanding of endocrinology, or more likely just didn't care, because it seems to be written on the assumption that you can determine someone's assigned sex at birth from a single hormone test, and (particularly with children) you can't.
