Remember when the Tampa Bay Buccaneers signed Josh McCown and I was all "he can probably be an okay game manager in the right system and with the right supporting cast"? Oops!
FiveThirtyEight tried to statistically categorize all of the quarterbacks in the NFL from 2006 onwards based on Total QBR, and they came to the conclusion that Josh McCown belongs in the group of "game managers." Of course, being in that group means your comparable playes are Jason Campbell, Matt Hassebleck, Alex Smith, Mark Sanchez, Josh Freeman and E.J. Manuel. Still pretty bad. I'm also not entirely sure as to why they call that group "game managers."
Amusingly, McCown also has the flattest distribution of Total QBR across his games. Essentially, he's mostly going to give you mediocrity and is equally likely to give you a good games as he is to give you a bad game.
So now you know: Josh McCown is a game manager. And not a very good one. Good thing the Bucs aren't starting him next year. I hope.