Who thinks the ban system is going to create the prisoner dilemma?

I think you have a good point, although most people, like in the prisoner's dilemma, are going to defect, as in banning the champion. People won't risk allowing a champion they hate, for instance Yasuo, to go unbanned, just in case the other team wants to pick him.

I think that's actually riot's goal. Though they probably didn't literally discuss incorporating game theory into the system.

Though, a problem will arise, if the "ban meta" becomes one which develops around the optimal decision in game theory (which it likely will as a result of the meta tending to follow pro players and they will make optimal decisions), then you will in fact end up with a significant amount of overlap. Even higher than what you'd expect given 5 bans independent of the other 5.

Could you clarify?

How so?

EDIT: Thought you were talking about account bans, not the champion bans. Never mind.

That's the whole fun about it though.