Even slimmer. An average NFL career is approximately 3.5 years. A below-average NFL career can be much longer, but only if you play for the Cleveland Browns. The players with the shortest careers are the ones who play positions where they get hit most often; running backs, wide receivers, and cornerbacks all average between 2.5 and 3 years. Kickers, punters, and quarterbacks have the longest average careers, but Morton Andersen and Brett Favre could be wrecking the curve.
According to the NFL Players’ Association, players with college earn between 20% and 30% more over their football careers than players without degrees, and have football careers that last about 50% longer. So just as in almost every other career on the planet, having more training and a college degree gets you a longer football career and more money.