Age is a bigger factor for running backs than for just about any other position in the sport of football. The 30-year-old mark is basically a death sentence for tailbacks, as age typically means a bulk of carries over long periods of time, and a bulk of carries over long periods of time mean a heavy dosage of wear and tear on the body.
This position may not be as deep as quarterback, our first installment of the 28 for 28 series, but it's still noteworthy, especially at the top, where All-Pro and Pro Bowl running backs are still lingering.