What about a universal ranked system. For example, take tennis. There are already ranking systems so imagine a single one where all players regardless of gender/age/etc are all on a single list. Competitions will only allow you to play against someone within X rankings from you. So regardless of gender/age/etc, matches will always be reasonably fair and people move up and down based on what they win or lose.

So, now comes the part of whose the best DESC. Want to know the top female, just see the highest ranking one? Top person over 50? Under 20? Top person who isn't taking performance drugs? Top person who is? etc. You can get whatever top ranking you want. All matches are fair. Everyone can play.