Trans girls/biological males competing against females

This is the research I think seems valid and also there is a "simple" example - Lia Thomas   https://bjsm.bmj.com/content/55/15/865?utm_source=chatgpt.com

Lia Thomas best time in 500 Free - 4:18-20 ....   -- then after the change - 4:33 -- lets take the 15 seconds --  difference in best times for 500 Free between male and female records 22 seconds... and overall this simple example does show a difference but simply not enough - and the article does show that muscle strength simple does not go down to a level that would make the competition fair. 

This is the research I think seems valid and also there is a "simple" example - Lia Thomas   https://bjsm.bmj.com/content/55/15/865?utm_source=chatgpt.com

Lia Thomas best time in 500 Free - 4:18-20 ....   -- then after the change - 4:33 -- lets take the 15 seconds --  difference in best times for 500 Free between male and female records 22 seconds... and overall this simple example does show a difference but simply not enough - and the article does show that muscle strength simple does not go down to a level that would make the competition fair. 

What it boils down to is the effect and not necessarily the time. Hence:

Lia Thomas's ranking in the 500-yard freestyle changed significantly after transitioning. As a man, she ranked 65th in the NCAA, while as a woman, she won the championship, ranking 1st. Her best time on the men's team was 4:18.72, while her best time on the women's team was 4:34.06