A quarterback in NFL football who is the best of the worst, or maybe the worst of the best. Whichever way you cut it, they cannot do anything spectacular whatsoever, but instead of being called shit and being grouped in with the rest of the turdbunch are given the much more friendly term of "game manager". They are the cream of the poopy crop. Game Managers do everything in their power to not shit the bed for their team that is usually winning in spite of them. They're shit.
In 2010 one might have called Mark Sanchez a Game Manager, in 2012 however it's pretty obvious he's not even that; he's just shit.