:OO get everyone onto a map where they can't leave for any reason but to quit. There they can use the storage all they want, it'll be a waiting room. Pick another map that isn't that big so taht players could fight, Recall 2 players at a time. Move winners into a new waiting room. D:
This idea takes like ... 3 GMs D: one to watch the first , another to watch the fight and another to recall into the winner room.