Future values of Peterson, Johnson

Adrian Peterson and Chris Johnson are elite, but are they worth big money given the position? US Presswire

If, in Week 1 of 2010, you were to combine the characteristics of the eventual top 12 rushers in the NFL, average them out and create a profile of the league's elite rusher for the season, you'd have a very capable human being. He would stand a hair under 6-foot-1 and weigh 217 pounds, a chiseled light heavyweight able to cover 60 yards in a breath more than six seconds.

He also wouldn't be able to rent a car without surcharges.

That's because the average age of the top 12 rushers in the NFL for 2010 was just 24.09 years old. So when you consider how incredible it would be to sign Adrian Peterson (a pending free agent) or Chris Johnson (likely a holdout) to your team after the 2012 season, consider that both will be, particularly for their position, well-aged, prime-cut talent by that time. If that sounds impossible, consider a dose of running back reality to start.

NFL draft evaluators often will say that the running back position offers the greatest opportunity for immediate success. But that's bordering on dark humor, something most readily admit. It's like saying that recruiters for Revolutionary War soldiers had an easy time selling the promotion potential -- when it's the job of the man in front of you to march into the musket crosshairs, yes, you can advance quickly.

"It is what it is," one NFL evaluator said. "It's not if, it's when. Is that a secret? We like to pretend it is." The NFL goes out of its way to protect quarterbacks, to the chagrin of some fans, and 100 percent of registered defensive ends. Last year, no NFL quarterback took more hits than Jay Cutler, who was hit 92 times, according to the league. So consider this: Johnson ran 316 times and caught 44 passes. He was hit presumably four times as much as Cutler, and that's before he threw a block.

Then consider this: Cutler outweighs Johnson by about 40 pounds.

This is why the average NFL running back doesn't last three full seasons, the shortest average career of any position group. These are the basic facts from the NFL Players Association, with 2.57 years cited in a recent study. And consider the cases of Peterson or Johnson: Of the top 12 rushers in the NFL last season, only Michael Turner of Atlanta was 28 or older in Week 1. But Turner is a special case. He had only 228 carries in his first four years. Both Peterson and Johnson eclipsed that total as rookies.