How do f keys spectate order work?

It feels random. Like I'm playing street brawl so I have four teammates including myself and left to right it's player 1, 2, 3, 4. But I press f1 and it goes to player 3 or something, I press f2 and it goes to player 1, idk it seems random

How do I make it go in order? Is there a way or is it just random 5ever