Maybe we should do this like pro wrestling championships - whoever the current "title holder" is gets to choose when to "defend" and what the bet is, and then defends against all takers. Or challengers can issue bets and the "champ" can choose to accept or not.
But when the title holder loses, his previous victims are released from their sentences. UNTIL he or she loses, all victims must keep their avatars. So for example sportsfan is stuck with david wright until somebody beats me
I'm probably overthinking this but eh, it's better than hoping for wins without a fallback