You've been a football fan long enough to know that when the starting QB gets hurt in a game the backup often comes in and lights a spark. The change in QB often throws such a monkey wrench in the other team's defensive plan that he (the backup QB) can win a bunch of games. Look at what Tebow did for the Donks last year. Look at what Orton did for us last year. Tebow won a bunch of games. Orton won a few....not because they were great QBs, but because defenses had no clue how to game plan for them. When a defense hasn't had a chance to study extensive film of a QB it's much harder to defense against him.
But in another way, Tebow is just as good as Cassel.... a fine backup but never a long-term solution at QB. I thought Cassel could be a long term solution at QB, but I was wrong on that. Time has proven it.