Backup Quarterbacks:
So what do people expect from a backup QB?
I'd say you need a decent one to go in for a few plays while your starter is tying his shoes or getting a different helmet and stuff like that.
You need one to fill in for a quarter if your starter gets dinged or even a game if push comes to shove.
But if your starter gets really hurt and is out for any length of time -- you're fucked. There isn't a backup quarterback in the league that can adequately fill in for the starting QB for 5, 6, or 7 games. If they win 40% of those games good for them. By then though you're toast anyway!
So again I'm not sure what the expectation is for the backup QB. It's crazy to think the backup comes in for Derek Carr and the team functions normally. Especially in the playoffs. That just isn't going to happen.
Bottom line is Cook is as good as probably any other backup QB.