1. I'm not sure that, in today's football world, you'll see too many top QBs make it through their senior year. I think it comes down to the number of starts in college, more so than the number of years, when it comes to a QB.
2. I'd say it is a bit more fluid than the average year, but we've certainly seen QBs rise significantly over the course of their final college season (Cam Ward last year, for example). Mendoza's rise is similar to Ward's in the sense that he transferred to a better situation and is now really shining.
