Ask HN: Need help with identifying type (name) of game theory

Does anybody know the name of the game theory where you pick players to play against one another? For example, you have a team of 10 fighters who need to fight another team of 10 fighters. Do you pick your best player to fight their best player? Second best to fight their second best? and so forth.

I know there is a name for this but I don't recall it. TIA