Adrian Peterson is worth slightly more than an orange peanut.
If you’ve been paying attention to the NFL for the past five or six years, you should have noticed the rise of the passing game. Passing records are rising, and modern quarterbacks are far surpassing the production of quarterbacks from just a decade ago.
The obvious assumption is that the increase in passing productivity should be slowly killing off the running game, making running backs less valuable each year unless they become a bigger part of the passing game. The predicted demise of the running game may be greatly exaggerated, but it does prompt an intriguing question.
What is the true value of a running back in today’s NFL?
It’s not an easy question to answer. Some types of running backs are undoubtedly worth more than others, and it’s hard to put a value on a running back who's part of a committee. You would also think that a running back who can catch passes would be an asset.
To truly get a gauge on the value of today's running back, we need to compare them simultaneously against each other and in relation to the passing game. There isn’t really a good way to do this, but there are a few things we can examine.
Run Ratio vs. Volume
There are two ways to look at the running game. One is to look at the ratio of running to total plays. A heavier weight would determine importance, which could be considered synonymous with value.
The ratio of runs to passes has fallen sharply over the past decade, from around 45 percent to around 42.5 percent. In those terms, the running game is roughly 3 percent less important now than it was a decade ago.
Over the past 10 years, the running game has declined as a percentage of attempts by about 0.3 percent per year. However, the ratio was pretty consistent from 2003-2006.
Since 2006, the running game has been declining at a rate of about 0.5 percent per year. This could be interpreted as a direct result of rule changes that favor the passing game.
This ratio is heavily influenced by the increase in passing attempts, so it’s possible that the running game isn’t getting less important, but that the passing game is just getting more important. A quick look at the number of team rush attempts per game reflect this to be the case for the most part.
From 2006-2007, the number of rush attempts per game dipped about one attempt per game, but the number of attempts per game was consistent from 2003-2006 and has been consistent from 2007-2012.
Of course, this is simply one piece of the puzzle to figure out how to value running backs. Rushing as a percentage of the offense is basically just demand; it doesn’t tell us anything about the supply of running backs.
A Workhorse vs. Running Back by Committee
In theory, the demand for a running back who could catch passes would also be more valuable than one who couldn’t, because the passing game is a bigger part of the offense now. This could manifest itself via more running-back-by-committee approaches in which one running back is the primary runner, while the other is more of a receiver.
After looking at the number of running backs that are getting 300 carries per season now as opposed to a decade ago, it’s pretty clear that the workhorse running back is rarer today. Over the past six years, there has been an average of just five such workhorse running backs per season.
With a decline in workhorses, we should see a rise in committees in which two or more running backs carry the ball at least 100 times. From 2004-2009, there was a spike in running backs carrying the ball 100 times or more, but that number has bounced around for the past few years.
In fact, after a 10-year high in the number of running backs who carried the ball 100 or more times in 2011, the NFL hit a 10-year low in 2012. There’s a lot of volatility at running back right now, which may indicate that the position is undergoing a bit of a transformation.
A Changing Position?
In theory, the passing game should give rise to receiving specialists at the running back position and a new breed of workhorse running backs who catch more passes at the expense of a few rushing attempts.
Indeed, running backs who are receiving specialists may have finally arrived in 2012. These are running backs who catch the ball a lot but don’t get many carries, defined for this purpose as a running back who caught 40 passes but ran the ball 100 or fewer times.
Last year, the NFL had more than twice as many of these specialists than any of the previous nine years. This could be the sign of an upward trend or simply an outlier, but the teams that produced these running backs were also good passing teams for the most part.
As far as a new breed of workhorse, they haven’t really materialized. The average number of running backs who have carried the ball 200 or more times and caught 40 or more passes over the last 10 years was 9.3, and there were nine in 2011 and 2012.
Running backs in general aren’t catching more passes either, as the average number of running backs with 40 or more receptions has been nearly constant. The average for the last 10 years has been 15.8 such players, and the NFL produced 15 in 2011 and 16 in 2012.
The average number of receptions of the Top 10 running backs each year is actually trending down. It’s clear that running backs have actually seen their role reduced in the passing game as quarterbacks are more willing to takes chances throwing to wide receivers and tight ends.
Adding it All Up
We know that the running game is only about 42.4 percent of the offense by volume of attempts and is declining, workhorse running backs are now scarce, and the passing game hasn’t really helped running backs outside of a handful of specialists.
The running-back-by-committee approach gained traction, but it may not be necessary going forward. The teams that do use multiple running backs now will likely have a lead running back and a guy who is basically a receiver, like the New Orleans Saints do with Darren Sproles.
Is the NFL ruining the game by slowly ruining the value of running backs?
It’s probably safe to say the value of a running back is at an all-time low given all of the relevant data. If the NFL’s new crown-of-the-helmet rule hurts the running game—even indirectly as the result of a cooling effect—it’s possible the value of the running back could take an even bigger hit.
NFL teams may already sense the demise of the running back, as the first one wasn’t drafted until the second round last April. In free agency, running backs came cheap if they were signed at all.
A workhorse running back—if you are lucky enough to find one—is at most around 40 percent by volume and weight of the offense. The 2012 Minnesota Vikings are probably the best case study, as running back Adrian Peterson accounted for 36 percent of the total offensive plays and 43 percent of the yards last year.
A running back who is part of a committee is worth closer to 12-20 percent of the offense by volume and/or weight of the offense. The three-headed running attack in New Orleans with running backs Mark Ingram, Pierre Thomas and Sproles is consistent with this approximation.
The true value of the running back is 3-4 percent less than it was a decade ago, but the running game is still an integral part of the game. Even the most pass-happy offense in 2012 ran the ball 33.7 percent of the time.