The problem I see with this discussion, in general, is that it deals with statistical averages and not individuals.
Indeed, would it be "fair" if the women in the right-hand side of the photo below compete against each other?
Also, would it be "fair" if the persons in the left-hand side of the photo below compete against each other if one of those persons was transgendered so that they both share the same gender identity?
(I just figured I'd add some food for thought to this discussion...of which doesn't seem to examine differences between individuals, whether they are the same sex and gender persons who compete against each other or different sex yet same gender persons who compete against each other.)
This movement of allowing transgender men compete in women's sports will end Women's Sports.
I have supported women's sports for decades, I attended College with Pat Summit and have been a supporter of women's basket ball from the day she took the Head Coach position at University of Tennessee.
She spent her life building the following of Women's Sports, (I will have to wash out my keyboard after saying this next statement) as did the Coach Gino of The University Connecticut.
It seems simple enough. If transgenders from male to female retain structural/physiological advantages such that their performance is more efficient than their competitors', then transgenders as a group will outperform unmodified females.
Do transgenders (male to female) perform @ the same level as unmodified males? If Yes, then that's where transgenders should be competing.
If No, then transgenders may have to compete in their own category.
How many transgenders (m. to f.) are we talking about here anyway? If the numbers are so small that pools can't be created for them to compete against each other, then the whole question may be moot.