Another point is that to go to the NFL, you have to be 3 years out of high school. A lot of times people will talk about "Juniors" coming out in the draft, but some of them are "Redshirt sophomores"....so they still have 2 years of sports eligibility remaining. Michael Vick was a redshirt sophomore when he came out. And like another poster pointed out, years in college has nothing to do with years in sports. Every once in a while a guy will get a sixth year of eligibility for sports if he had a particular medical hardship...so that guy is taking grad school courses....