Jay Ajayi and Melvin Gordon Are Showing the Importance of a Healthy Offensive Line

Two weeks ago, Melvin Gordon was averaging almost three yards per carry. Touchdowns were buoying his fantasy production, but from an efficiency standpoint, Gordon was leaving plenty to be desired.

Around that same time, Jay Ajayi was mired in a backfield committee with the Miami Dolphins. He hadn't topped 42 rushing yards in a single game, and Arian Foster was on the verge of returning from an injury, threatening Ajayi's already-limited role.

You could say the past few weeks have been a bit more fruitful for both.

Gordon has topped 110 rushing yards in consecutive games, including a 196-yard performance Sunday against the Tennessee Titans. Ajayi's 111 rushing yards in Week 9 marked his third straight game above 100, including a pair of 200-yard days leading up to their Week 8 bye. They've gone from wallowing in inefficiency to dropping silly sauce on the entire league in almost no time.

When we have performances like these, it's always best to be cautious before fully buying into the shifts. Outliers happen all the time in the NFL, and we could simply be seeing the players string their best games of the year together at the same time.

There's one factor, though, that makes this explanation seem a bit less likely. It all boils down to the health of the men paving the way up front.

Let's take a closer look at both Gordon and Ajayi to see the role offensive line health has played in their respective seasons. This will illustrate the importance of tracking offensive line health when evaluating the performance of running backs. Then, we'll use this thought process to spot a couple areas of note as we move forward with the season.

Breakouts Coinciding With Increasing Health

Let's start with Gordon, who actually endured this same pain last year. The San Diego Chargers' offensive line fell into shambles around Week 4, and Gordon's performance from then on out heavily reflected this crumbling. It almost happened again earlier this year.

Back in Week 3, left tackle King Dunlap was a surprise inactive against the Indianapolis Colts while dealing with severe migraines. Gordon finished the game with 16 carries for just 35 yards without the blindside anchor on the line.

Things didn't get better in Week 4. Dunlap had to sit again with the migraines, and both left guard Orlando Franklin and right tackle Joe Barksdale hopped in and out of practice throughout the week. They wound up being active, but they clearly weren't at full health. As a result, Gordon plodded along to just 36 yards on 19 carries.

Ever since, though, all five of the Chargers' starting linemen have been fully healthy, and Gordon has successfully avoided the duds. This all culminated in his back-to-back big weeks with one coming against the vaunted Denver Broncos defense.

This table shows Gordon's splits in the games where Dunlap has been able to play versus the two he missed. Rushing NEP (short for Net Expected Points) is the metric we use to track the expected points a player adds to his offense when he touches the ball. Success Rate is the percentage of plays on which the player increases the team's expected points for the drive. This shows just how important the big guys up front are to Gordon's recent run.

With Dunlap, Gordon's Success Rate is still slightly below the league average for high-volume running backs (41.52%), but he's at least respectable. His Rushing NEP per carry when Dunlap plays is above the league average of 0.00, meaning he's just a solid rusher. Without Dunlap, things were abysmal.

We can see a similar story develop with Ajayi and the Dolphins. Center Mike Pouncey missed the first four games of the season due to a hip injury. They were slated to get Pouncey back in Week 5, but left tackle Branden Albert missed that game due to an illness, and left guard Laremy Tunsil slipped in the shower and was out, as well. Tunsil was supposed to fill in for Albert at left tackle as he had done in Week 4, so they were scraping hard to find healthy bodies.

They were healthy in Week 6, though, and oh boy, did those puppies move Earth.

That was the game where Ajayi shredded the Pittsburgh Steelers for 204 yards and 2 touchdowns on 25 carries. The first game where Pouncey, Albert, and Tunsil were all active was the one where the offense took off. That's probably not a coincidence.

Here's the same chart from above, except focusing on all Dolphins running backs as opposed to just Ajayi. Once the offensive line got healthy, they turned things around in a hurry.

They went from slightly below average to "Ooohh, y'all ain't gotta hurt 'em," with the flick of a switch. Again, this is far from being a coincidence.

Both Gordon and Ajayi have gone full death mode the past few weeks, and we can easily trace it back to their offensive line's health. That's great for them, but what does it mean looking forward? It means there are a few situations of which we need to be aware.

The Good, The Bad, and The Ugly

Let's start things off on a cheery note here, and that comes via Lamar Miller. The Houston Texans played their first four games of the season without left tackle Duane Brown, and Miller's Success Rate while going left in those games was 29.40%. In the four games since Brown's return, that has jumped all the way to 52.63%. The Texans have a baller schedule going forward, and Miller could continue to thrive now that Brown is back.

Things aren't quite as rosy for the Arizona Cardinals. They already lost right guard Evan Mathis earlier this season, and now left tackle Jared Veldheer is on injured reserve with a torn triceps. Carson Palmer lost an absurd 17.47 NEP due to sacks in Week 8 alone -- the game in which Veldheer got injured -- and Veldheer's absence could dampen the outlook for guys like Palmer, Larry Fitzgerald, and even David Johnson. Johnson is beastly enough where he should still be fine, but this is a situation we will have to monitor regardless.

When Spencer Ware is able to return to the Kansas City Chiefs, the assumption is that he'll be able to become a top-shelf running back again. While that could be true, we also need to proceed with caution. Left guard Parker Ehinger is on injured reserve with a torn ACL, and the team has struggled without him.

In the four games in which Ehinger was able to play at least 50% of the snaps, the Chiefs averaged 0.02 Rushing NEP per carry. In four games without Ehinger, that number falls all the way to -0.25. Ware's a great back, but it's fair to be skeptical about the situation he'll inherit once he's out of concussion protocol.

If you're looking for 2016's version of the Chargers, look no further than the Minnesota Vikings. They've lost their left tackle and right tackle for the season, left guard Alex Boone missed Sunday's game with a concussion, and the rest of the line has been a wreck. This means Jerick McKinnon's rest-of-season outlook is beyond bleak, and we shouldn't expect the offense to hum along too efficiently.

This does mean, however, that we can turn to those pieces when looking forward to 2017. The public will be down on the Vikings due to what will likely be an ineffective 2016, but with an offseason to get healthy and invest in the line, whoever winds up as the lead back should figure to have a big bounceback next year.