Should the Carolina Panthers Use an Early-Round Draft Pick on a Running Back?

Many Carolina Panthers fans recognize that the tight cap situation their team faces is an indictment on former spendthrift General Manager, Martin Hurney. Hurney, fired from the Panthers in 2012 after a decade with the team, apparently became heavily influenced by the actions of Pacman Jones near the end of his tenure, and decided that making it rain millions of dollars on not one but two star running backs was key to the Panthers' success.

Both of these backs, DeAngelo Williams and Jonathan Stewart, received five-year contracts totaling $43 million (Williams, signed in 2011) and $36.5 million (Stewart, signed in 2012), respectively. The problem was that Double Trouble, the moniker given to the duo that set an NFL record for being the first teammates to rush for over 1,100 yards in the same season in 2009, never replicated their successes in tandem after their massive contracts were signed.

But in 2014, Stewart seemed to find either an invisibility cloak or some calcium pills, staying healthy for the final 10 games of the season while rushing for over 800 yards and finishing the year with an impressive 4.6 yards per carry.

With Williams’s contract now off the books, many Panthers fans may feel it's financially prudent and strategically wise to keep riding Stewart as the team’s undisputed starting running back in order to plug up other holes in the draft, including finding a stud offensive tackle, or finding another monster receiver to line up opposite Kelvin Benjamin. Which is why some fans probably did The Exorcist head turn when they heard that the University of Georgia’s star running back Todd Gurley, recent ACL tear and all, recently met with the Panthers as the club does their pre-draft due diligence.

But was Stewart’s 2014 year so impressive that it warrants not looking at some of the top running back talent in this year’s draft?

Stewart’s 2014 Performance

Thankfully here at numberFire, we are equipped to grapple with this question by quantifying a player’s true effectiveness via our Net Expected Points (NEP) metric. The gist of NEP goes like this; each play in a game has a value in terms of points that it is expected to yield. If a running back tallies a three-yard run on a 3rd-and-8, they have contributed less to their team in terms of expected point yield than if they break out a three-yard run on 3rd-and-3. One is a positive play resulting in a first down, while the other contributes nothing. Thus, the difference in the expected point yield and the actual performance above or under expectations is the player's total NEP for that play. To learn more about NEP, visit our glossary.

In Jonathan Stewart’s case, he was playing behind one of the worst offensive lines in football last year. Anyone who watched the Eagles-Panthers game where Cam Newton was flattened like a pancake to the tune of nine sacks can attest to that. But pass protection and run blocking are two different animals, and according to FootballOutsiders.com, Carolina was even worse at creating holes for its rushers than it was at creating time for Cam to throw, ranking as the 27th-best run blocking line in 2014.

In order to compare Stewart to running backs with similarly ineffective run blocking offensive lines, I've compiled NEP stats for running backs amassing over 125 carries in 2014 on the teams ranked 21st through 32nd in run blocking.

Running behind a porous run blocking offensive line is tough, even for good running backs. In fact, only three of the 15 rushers above matched or bested the NFL league average for rushers since 2011 on a per rush basis (-0.02 NEP for running backs totaling over 50 carries in a season). But Stewart ranked only 8th out of 15 qualifying rushers in Rushing NEP and 7th in Rushing NEP on a per rush basis among qualifying running backs on these teams.

Stewart did, however, boast the third highest Success Rate (the percentage of plays contributing positive NEP to a player’s total NEP) among this group, besting former rushing title luminaries including Lesean McCoy and Arian Foster.

Interpreting this can be tricky, but basically, a higher than average Success Rate combined with a below average Rushing NEP per rush suggests that the composition of Stewart’s successful plays were more tilted toward short-yardage successes as opposed to breaking off big runs. This is borne out by the evidence: Stewart broke off only three carries totaling 20-plus yards in 2014.

Also a drag on Stewart’s NEP score is the fact that he rushed for only three touchdowns in 2014. This may be less indicative of his performance, however, because Cam Newton, according to the Pro-Football-Reference.com's Game Play Finder, commanded a slightly larger percentage of the team’s total carries (32%) when five yards or less away from the end zone than did Stewart (28%)

Stewart has had success in the NFL, particularly in 2008-2009 and 2011.

To Draft or Not to Draft?

Stewart’s injury-riddled 2012 and 2013 seasons have to weigh on the minds of coaching and personnel staff in assessing whether his pre-2012 magic can be rekindled. If they’re going off of his performance in 2014 in making that assumption, they may be deceiving themselves. His performance just wasn’t as electric as some of the Panther faithful might believe.

To clarify, more solid offensive line play would likely help boost Stewart’s effectiveness. But having exhibited average production on a per rush basis in comparison with running backs behind similarly woeful offensive lines, coupled with a history of injury concerns, suggests that the Panthers riding Stewart as their bell-cow could be sub-prime-mortgage-loan risky. Considering that, it'd probably be wise for the Panthers to use their first two rounds to grab a stud offensive tackle and their running back of the future, thus introducing the second iteration of Double Trouble. At least in that case, one of the "troubles" would take up significantly less cap space.