The sad, dreary, protracted mating ritual of veteran running backs and needy franchises is finally over. Chris Johnson is now a member of the Jets, Maurice Jones-Drew is now a member of the Raiders, and every other running back approaching age 28 is terrified to let his contract lapse or his productivity slip even a tiny bit.

CJ2K and MJD are so famous I can refer to them as CJ2K and MJD without fearing an editor's note or angry emails. Their combined résumé includes five Pro Bowls, two rushing titles, and a storied 2,000-yard season. Both are beyond their glory days, but neither turns 30 until 2015. All of their highlights are in high-def.

Both lingered on the open market for days. Jones-Drew waiting through the initial free-agent flurry before landing with a cash-flush team strangely fascinated with building a 2009 Pro Bowl roster. Johnson, quietly released by a Titans team with zero offense stars, twiddled his free-agent thumbs for days before signing with the Jets, who appear determined to use him and Michael Vick to build the ultimate last-gen game console Madden team. The rushing champions of three years ago are this year's budget-friendly afterthoughts.

They don't make superstar running backs like they used to. But actually, they never really did.

When boom went bust

Give the Jets credit: They have had a serious need for years, and they filled it with a player who could have filled that need years ago.

The Jets have had two runs from scrimmage longer than 40 yards in the past three years. They needed a big-play threat for their backfield committee full of bruisers. Unfortunately, Johnson is all threat with no big play these days.

Johnson's longest run from scrimmage last season was 30 yards. He was a boom-or-bust back with no boom. He brought the boom with three 80+ yard runs in 2012, but those plays accounted for 20 percent of his overall production, and he needed 276 carries to generate them. Johnson had some long runs on screen passes last year, and it is safe to say he still has the speed to outrun a defense if he finds some open space. But the 5,300 square yards of a football field rarely contains enough space for him these days.

Chris Johnson vs. Average NFL RB
Run Length CJ2K, '12-'13 NFL Avg.
Negative 12.6 % 10.1 %
No gain 8.5 9.5
1 yard 11.0 12.5
2 yards 12.6 13.6
3 yards 13.2 12.2
4 yards 9.4 9.9
5 yards 8.5 7.4
6 yards 3.8 4.9
7-10 yds 11.2 11.1
11-15 yds 5.4 4.9
16-20 yds 1.8 1.8
21-30 yds 1.3 1.1
30+ yds 0.7 1.0

The breakdown of Johnson's rushing production, based on the length of his runs and shown at right, does not show a terrible running back. In fact, it shows a roughly league average back, albeit one who gets stuffed more than most but makes up for it with some midrange runs. The most alarming percentages are at the bottom of the table: even with his 80-yard explosions of two years ago, CJ2K is no more explosive than the average running back.

You may have expected worse: Average is, well, average, and Johnson provides value as a screen pass threat and serviceable pass protector. Here's the question: How much would you pay for an average running back? Average running backs are not like "average" quarterbacks, who are really fairly rare. There are dozens of players around the NFL who, given 250 carries or so, will creep up on 1,000 yards. Teams routinely find them on the bench or in the fourth round of the draft.

Jets GM John Idzik, with little pure speed anywhere on his offensive depth chart, decided Johnson's version of average was worth $8-million over two years: a living wage, but not the salary of a recent superstar. Raiders general manager Reggie McKenzie asked himself a similar question a few weeks ago and decided Jones-Drew, a 1,600 yard rusher two years ago, was worth far less.

No guarantees

We could run a chart for Jones-Drew like the one we ran above for Johnson, but MJD's 3.4 yards per carry tell you most of what you need to know. Of MJD's 234 carries, 125 of them - that's 53 percent -- produced two yards or less.

Jones-Drew has had just two 100-yard games in the past two years. He had games in which he carried 21 times for 41 yards last year, 13 times for 23 yards, 14 times for 23 yards. MJD was a Pro Bowler in 2011, but 2011 is a long time ago. Over the last two seasons, he made Chris Johnson look like vintage Franco Harris.

The Raiders realize this, of course. The team with beaucoup cap bucks and a roster reminiscent of the defunct UFL has spent a little too much effort assembling superstars of the late 2000s like Justin Tuck, Lamarr Woodley, Matt Schaub and MJD, but they have not gone crazy spending money. Jones-Drew earned a $1.2-million bonus and a modest, non-guaranteed three-year contract from the Raiders. The team could conceivably release him in August, though that is unlikely for the talent-starved Raiders. Veteran special teamers earn more impressive deals. It's chilling when you consider just how huge a star MJD was 24 months ago.

It is tempting to look at the recent performances of Jones-Drew and Johnson and rationalize. Both have spent the last several years in screwed-up organizations with bad offenses that could never take pressure off the running back by figuring out their quarterback situations. All true. Johnson and Jones-Drew are now moving to the Jets and the Raiders. Out of the frying pan, and all that.

The Jaguars and Titans are not to blame for the declines of MJD and CJ2K. Age is the primary culprit. Analysis is the accomplice. Running backs age early and age suddenly. The number crunchers in NFL offices have finally figured out just how early and suddenly, and they are adjusting running back pay scales with ruthless efficiency.

Downward trajectory

We can all make a list of running backs who had long careers: Curtis Martin, Emmitt Smith, Marcus Allen, Jerome Bettis, John Riggins and so on. Two things start to happen after we begin listing. 1) We realize we are all listing the same players. 2) We rapidly begin running out of players, even with decades of history to draw from. Those are signs that the lists are actually rather short.

If we do a little research, we also start to notice that some of our "last forever" guys did not last as long as we thought. Franco Harris stopped reaching the Pro Bowl when he turned 30. Eric Dickerson had his last good year when he was 29. Even Bettis stopped cracking 1,000 yards at age 29, settling into a late career as a committee back, short yardage specialist and civic treasure. Allen did roughly the same thing.

Star running backs burn bright and short. Chase Stuart of Football Perspective has been calculating just how bright-and-short the typical running back's career is for years. His most recent data tells a sad story. Quality running backs -- not bench warmers, but regular starters who amass a few hundred carries -- peak at age 26, then decline smoothly and rapidly. The graph accompanying his research says it all. One-thousand yarders at age 25, as a group, are struggling to maintain regular roles by age 30.

It is bad analytic form to apply a general curve like Stuart's to specific players. There are C-Mart types who play forever and Bettis types who thrive as situational role players. But when the age curve matches up with other evidence, it all leads to the same conclusion.

Johnson and Jones-Drew have already shown obvious signs of age. History tells us that those signs of age are no fluke, but a natural part of the typical career arc of a running back. They are getting old, fast.

Teams are wise to all of this now, though they may not have been a few years ago, when the Seahawks gave 29-year old Shaun Alexander a reported $62-million extension so he could decline with sudden style. The most vibrant field in the "football sabrmetrics" realm is the analysis of salary cap dollar efficiency. Teams are using data to make sure they do not extend contracts too far past a player's expiration date, unless they are doing so specifically for funky-accounting purposes (in Texas it is called Romonomics). Idzik and McKenzie know MJD and CJ2K are fading fast. They also know there may be windows of usefulness left, particularly on rosters bereft of skill-position talent or big-play capability. Hence, modest two-or-three year contracts with almost nothing guaranteed but a quick-and-cheap exit if either player's yards-per-carry recedes much faster than a hairline.

In a separate essay and using different methods, Stuart projects an optimistic 1,000 yard, six-touchdown, 3.8 yard-per-rush season for Johnson. It sounds great until you realize Chris Ivory and Bilal Powell were far better than that on a per-carry basis for the Jets last year. Still, that would be solid production, particularly if some 60-yard scampers are mixed in. And at the Jets are not expecting great things in 2016.

The depressed market

The good news is CJ2K and MJD will earn more money than you or I make to prove the doubters and statistic wrong; the Jets and Raiders acquired the services of interesting players at bargain prices and better data usually leads to better business decisions for all parties, at least in the long run.

Here's the bad news.

All rookies sign four-year contracts now, with zero negotiating options for the first three years and minimal maneuverability in the fourth. First-round picks get excellent salaries, but first-round running backs are becoming an endangered species. Everyone else gets what they get and, with some minor adjustments, spends a presidential administration not getting upset.

A four-year contract takes a 21-year old rookie running back through his 25th birthday. By the time he reaches the open market, he is essentially at his peak and ready to decline. General managers are aware of this and increasingly reluctant to hand out huge paydays.

Running backs are traditionally football's second-biggest stars. They grace the covers of media guides and spur jersey sales and fan imaginations. They also incur more physical risk than any other player. No one else on the field is subjected to 20 tackles per game by players 50- to 100-pounds heavier than them. But despite the pain and prestige of their jobs, running backs are losing their ability to profit from their fame. Their salaries and negotiating leverage are melting away on both sides.

Running back is rapidly becoming the worst job in professional sports. Johnson and Jones-Drew at least got the opportunity to cash in with their previous contracts. The current generation won't be so lucky.