I agree that Alabama and Ohio State were two of the best defenses in the country. Although I personally believe you can see a lot from how a guy faces Nebraska, Boston College, and Oklahoma as well. And Iowa. Not ready to toss those out and pretend they don't compare with Alabama and Ohio State. They do. But there's no doubt that some guys particularly Gabbert seem to be given a free pass versus Mallett...probably because of the character thing.
Too much is made of Mallett's performance against Bama. Three bad interceptions, no doubt about it. But otherwise he had two or three times more good plays than bad, and that was being very nitpicky with the bad plays. He needs to learn when to give up on a bad play. That's one of his most consistent problems, when he does screw up.
And I felt Mallett's Ohio State performance was about equal to Gabbert's Iowa performance, both good overall against good pass defenses. Both threw the critical interception at a bad time. Both were generally throwing the ball all over the field and throwing well for most of the game. Mallett's got a better history against better defenses. Also a better cast though.
Yes, you can see enough from watching quarterbacks play against Nebraska (especially), Oklahoma, Boston College, and Iowa to get an evaluation, but they're not the same thing as facing Alabama's defense.
Every quarterback that has faced Bama's defense over the past 2 years usually either has their most dreadful outing of the season (or career), gets knocked out of the game... or both. You just can't say that about these other teams, it's a different test going up against Saban's Alabama defense. The physical and psychological strain on a quarterback is different.
Gabbert has NO history against good defenses other than a bad one on the rare occassion he was able to face one. Defenses that are considered "good" from the Big-12 aren't on par with the defenses from the SEC. Defenses from the B1G that are considered "good" are a little closer to what the SEC can throw at you every week... mainly only Ohio St. and Iowa. (not counting new B1G member Nebraska).
I think we've attempted to make the best case we can possibly make in order to help people realize that Ryan Mallett is not this gimme sack that people think he is. In fact, he's sacked about 1 in every 16 drop backs, whereas that beast of an athlete Cam Newton is sacked about 1 in every 12 drop backs facing the same defenses.
Blaine Gabbert is sacked less than BOTH of them, but you damn sure can't tell it by watching him play. Jake Locker is sacked more than any of them, at least he has a reason for his lack of accuracy and ability to function like an elite QB prospect from inside the pocket, without even mentioning the fact that he didn't have a checkdown option these other QB's had. His running back always had to stay in and block due to the offensive line being so poor. Locker either had to complete the pass to scrubs down the field, take off and run with it, or eat it. The checkdown option to help pad his completion percentage or take the pressure off his pathetic offensive line trying to sustain blocks wasn't there. The fact that he didn't turn the ball over more than he did considering the circumstances, and his TD/INT ratio is better than Gabbert's despite playing with an even more inferior supporting cast is a credit to him.
Gabbert's supporting cast is a lot better than Locker's, and still couldn't perform better than Locker despite both playing the same Nebraska defense twice over the past 2 years. However, Locker does have a "W" against the Huskers despite his receivers getting run out of bounds 10 yards into their route, Gabbert doesn't.