re: How many quarters will Denard Robinson last against Saban's defense?

Depends

If Hoke uses him like I think he will he plays the whole game and gets some good plays in.

If Hoke decides to use him like Tebow and fullback him up the middle and continually run him down the line he stands a good chance of getting knocked the frick out. Bama is not going to go full out pass rush on him. It will be a soft containment rush that primarily attempts to keep him in front of the defender and will only aggressively engage past the LOS

JMO