It's Time for the Houston Texans to Cut Arian Foster

Running back Arian Foster has almost 1,500 carries and countless injuries on his ledger. Is he wearing down?

One of the greatest movies of all time has to be the American classic Lethal Weapon.

Los Angeles homicide detective Roger Murtaugh -- played by the inimitable Danny Glover -- is nearing his retirement, when he’s pulled back in for one last case. As the tension mounts before chase scenes roar off, shootouts explode, and conspiracies become revealed, Murtaugh tends to mutter to himself, “I’m too old for this [stuff]”.

Still, as is noted by one of the characters in How I Met Your Mother, even though Murtaugh always says he’s too old for [stuff], he keeps coming back to do more stuff.

While he may not be considering retirement, Houston Texans running back Arian Foster has to be wondering if he’s getting too old for the National Football League. Just this week, a report came out that the Texans would consider releasing him this offseason as they continue their rebuilding process.

With Foster going on age 30 and currently only three months removed from a torn Achilles tendon -- not to mention the groin tear that sidelined him in training camp -- does he still have it in him?

Should the Texans move on from Arian Foster?

Loose Cannon

First and foremost, we have to explain the case of why the Texans would even consider the notion of cutting their star runner. He's due a non-guaranteed $6.5 million base salary next year, but is not guaranteed to be his usual self. Foster will turn 30 next August, and while we at numberFire have proven in the past that that isn't a certain death knell for his fantasy career, there are other factors surrounding him that give cause for concern.

For instance, our own Joseph Juan did a study last offseason on how running backs’ career workloads -- rather than age -- are a warning sign for late-career production plummets. Joe’s study showed that the 1,800-carry mark is the beginning of the end for a running back in the NFL. Foster only has 1,454 career rushing attempts to this point, but he has more than the typical amount of wear-and-tear. Even examining just the running backs Joseph used in his study, Foster has a heavier carries-per-game workload (19.13) to this point in his career than all but LaDainian Tomlinson (21.63), Jamal Lewis (20.11), and Clinton Portis (20.37).

In addition, Foster has played in just 76 of a possible 112 games in his career (67.9 percent) due to a myriad of injuries ranging from turf toe to tendon ruptures to labrum tears. He may be just turning 30 next year, but his body’s age seems way too old for this stuff.

Hollywood Boulevard Chase

All of this is speculation on what happens on the average, however, and we know that every player is a unique circumstance. If we want to understand the trajectory of Foster’s career from this point forward, we have to look at his production.

numberFire has a metric called Net Expected Points (NEP) which will help us to do just that. NEP is an analytic helps us take the numbers we get from the box score and shows how that player did versus expectation. By adding down-and-distance value to standard box score information, we can see just how much each play and each team as a whole influence the outcome of games. A rushing gain for five yards on 3rd-and-2 means more to the game than it does on 3rd-and-10, and those plays should be valued accordingly. For more info on NEP, check out our glossary.

With Foster, we want to examine both his Rushing NEP and Reception NEP to find out if there is a pattern he’s following. The table below shows the NEP and his ranks among running backs with at least 50 opportunities annually for Foster’s career. What do we see?

Year Rush NEP Per-Play Success Rate Rec NEP Per-Play
2009 6.85 (19th) 0.13 (t-4th) 53.70% (3rd) 4.57 (56th) 0.51 (t-12th)
2010 27.90 (3rd) 0.09 (9th) 46.63% (15th) 40.68 (1st) 0.48 (15th)
2011 -3.60 (40th) -0.01 (t-32nd) 43.73% (24th) 34.39 (3rd) 0.48 (t-12th)
2012 -6.68 (50th) -0.02 (t-35th) 41.88% (41st) 3.38 (54th) 0.06 (t-72nd)
2013 0.52 (28th) 0.00 (t-28th) 43.80% (20th) 7.12 (39th) 0.20 (t-48th)
2014 8.51 (13th) 0.03 (t-17th) 39.23% (51st) 27.28 (6th) 0.46 (14th)
2015 -15.25 (77th) -0.24 (85th) 38.10% (46th) 17.84 (24th) 0.64 (6th)

The numbers don’t look good for Foster’s hopes of redeeming and resuming his career in 2016. His total Rushing NEP value has been poor for three of the last five years, and better than average just once since his top-three 2010 season. His per-play Rushing NEP looks even worse than this, and he slipped to a horrendous 85th out of 88 qualifying runners last year in that metric. Was he injured still? Possibly, but that is part of the deal we get with Arian Foster: the potential for him to play injured and inefficiently. Even more consistently downturning, his Rushing Success Rate -- the percentage of attempts in which he creates positive NEP value -- has progressively gotten worse every year except for a surge in 2013.

Charting this data helps put these metric declines in perspective (the black line shows the normalized linear progression throughout Foster’s career). All of the rushing values are on downward trajectories, and the per-play value is perhaps the most worrisome of all; removing volume from the equation helps us get closer to a player’s true ability, and it’s clear from this that Foster’s has eroded. The graphs below show his Rushing Success Rate and Rushing NEP per attempt in visual form.

Rushing Success Rate

 Rushing NEP per play

The one component of Foster’s game that has remained stable is his receiving ability, however, both on a total and per-play Reception NEP basis. Should he decide to keep playing in 2016, he could find work in a committee somewhere as a receiving back.

It’s a shame to say, but all of the data seems to indicate that the sun will set on the career of Arian Foster sooner, rather than later. He is an incredible player who has had an incredible career, but if the Texans are ready to move on from him, it’s unlikely he has more than a few years left in his legs. Should Foster retire this offseason, though, he will have earned his right to turn in his badge proudly.