A "female only" and "open" category works for sports like athletics. But it doesn't work across the board for individual sports like wrestling, boxing and judo, or for team sports that involve tackling, body blows and pile-ons like rugby and American football. Nor does it work for other sports that involve a lot of rough physical contact such as checking, elbowing and accidental collisions; ; or which involve the likelihood of players hitting each other with implements like hockey and lacrosse sticks, or being struck in the head or neck by projectiles traveling at high speed like balls and pucks.
The focus of my posts on LRC is mainly on insuring safety and fairness for female people who do sports by confining the girls' and women's category to those who are female. But I also believe that it would be unfair to male athletes if all the sports that guys do were forced to become mixed-sex.
Some sports like volleyball, field hockey and tennis doubles already have rules for mixed-sex play that insure fairness and safety for female players whilst still trying to keep play challenging enough for male players. But let's face it, the experiences of playing and watching mixed-sex volleyball, field hockey and tennis doubles are very different to playing and watching female-only and male-only matches in these sports.
I think that boys and men should be able to practice and play volleyball, field hockey, tennis doubles, rugby, ice hockey, basketball, soccer, American football, water polo and other sports amongst themselves in siutations and according to rules that don't require them to hold back or make allowances and accommodations for the different physical size, strength, speed and susceptibility to injury of female team mates or opponents.
I think that boys and men who do sports should be able to take a leak, change their clothes, shower, take saunas and steam baths, etc. and engage in "locker room banter" in facilities that are male-only too.