How many turns before deadbeating

I was just curious what the number of turns a person must miss before getting kicked out is, and what it depends on.
I've seen people get booted after missing only 2 turns, and I've seen them go as many as 4 and still be active.
Is it based on total players in the game, or current round or something like that?
I've seen people get booted after missing only 2 turns, and I've seen them go as many as 4 and still be active.
Is it based on total players in the game, or current round or something like that?