The 5 Best Run-Blocking Offensive Lines in 2015

Using numberFire's metrics, which offensive lines appeared to provide their teams the greatest boost in 2015?

Sometimes the big fellas gotta get a little love, too.

Because of my constant focus on fantasy football, I have a tendency to get enamored with the running backs, wide receivers, and quarterbacks of the world. After all, these are the glory positions whose production is easy to quantify, whether it be through raw stats or advanced metrics.

That's not the case for offensive linemen. Sure, you'll find sites now that will grade them on their performance, but that is not nearly as abundant as the love their skill-position counterparts receive.

However, it's hard to deny the impact a great offensive line has. We've seen that teams often immediately benefit from drafting an offensive lineman in the first round. Additionally, there are often instances in which one running back will go down, and his back-up will immediately sustain the previous levels of efficiency. It's time to give these fellas their due.

Using numberFire's Net Expected Points (NEP) metrics, let's try to decipher which teams had the best run-blocking offensive linemen in 2015.

NEP is the metric we use to measure the efficiency of an offense. Unlike a yards-per-carry total, this will reward a team for picking up three yards on 3rd and 2 rather than punish them. If they get the job done and increased the team's expected points on their current drive, then NEP will reflect that. The team numbers are adjusted based on strength of schedule, while the individual numbers are not.

Obviously, this is far from an exact science. We can't just magically take the running back or other factors out of the equation. That's why you're not going to see a team like the Minnesota Vikings below; it's hard to separate which portions of the credit should go to the offensive line and which go to Adrian Peterson for being a freak in the most positive sense. 

Rather, I looked for teams who saw success with multiple running backs toting the rock. If there were three running backs on the same team who all had positive metrics, that would likely be indicative of a top-tier offensive line.

With all of this said, here are five offensive lines who allowed their offense to put in work on the ground this season.

Kansas City Chiefs

Most Common Starters: Eric Fisher, Jeff Allen, Mitch Morse, Laurent Duvernay-Tardif, Jah Reid

When you lose a perennial Pro-Bowl running back midway through the year and proceed to rip off 10 straight wins, you're doing something right. The Kansas City Chiefs more than fit that bill.

Even with Jamaal Charles' injury, the Chiefs finished the year ranked second in Adjusted Rushing NEP per play. Charles deserves part of the credit for that, put the drop off to Charcandrick West and Spencer Ware wasn't dramatic.

The strength of the Chiefs' offensive line was straight up the gut. On runs up the middle, no running back with a minimum of 20 carries had a higher Rushing NEP per carry than Charles. Additionally, he, Ware, and West all had above-average Rushing Success Rates on runs in the middle.

On the year, there were 58 running backs who had at least 70 carries. Charles had the fourth best Rushing NEP per carry of that group, but he still didn't lead the team in this metric; that honor belonged to Ware, who finished second. West was lower in 33rd, but placing two players in the top four has to land you some sort of recognition.

What may make this even more impressive is that the line wasn't without its own injuries. Ben Grubbs missed the final nine games with a neck injury, and no player started all 16 games (though Fisher was active for all 16). There are a lot of reasons the Chiefs made the run they did to the postseason, but the offensive line needs to be high on that list.

Buffalo Bills

Most Common Starters: Cordy Glenn, Richie Incognito, Eric Wood, John Miller, Seantrel Henderson

Bringing in a player with as much controversy around him as Richie Incognito can seemingly either be a major boon or a crippling bane; this would appear to be the former.

The Buffalo Bills finished the year as the league's most efficient team on the ground, even though they, too, saw injuries to running backs. LeSean McCoy missed four games, and Karlos Williams missed five, yet both were hyper efficient when healthy.

Let's focus on Williams first, as he was the cream of the crop when he got his chances. He still counts as a low-volume player because he only had 93 carries, but Williams led all players with at least 70 carries in Rushing NEP per carry. In fact, at one point, he was the most efficient running back since the turn of the century among those with at least 50 carries in a season. This supreme Gucciness only increased when he hit the left side of the line.

I use color scales on most of my spreadsheets to help me visualize where teams excel and where they lag; I can't do that when charting running backs rushing to the left. Williams' mark is such an outlier that it distorts everything else.

On his 26 carries that went left this season, Williams racked up 16.85 Rushing NEP and 0.648 Rushing NEP per carry. The second best mark in the league belonged to Le'Veon Bell at 0.238 Rushing NEP per carry, over a 63 percent decrease from Williams. My face is melting from looking at these numbers.

This isn't to discredit McCoy, who also had a fine season, finishing 18th in Rushing NEP per carry of the 44 backs with at least 100 carries. It's just emphasizing how ridiculous Williams was and how consistent the team was regardless of who was getting the carries.

Given Williams' effectiveness running left, it should come as no surprise that the left side of the line -- Incognito, Cordy Glenn, and Eric Wood -- was able to start all 16 games this year. Losing Seantrel Henderson to Crohn's disease was certainly a tough blow, but the team still logged a solid initial campaign together in 2015.

Arizona Cardinals

Most Common Starters: Jared Veldheer, Mike Iupati, Lyle Sendlein, Ted Larsen, Bobby Massie

This one really shouldn't need more explanation than they made Chris Johnson into a passable running back. A feat of such improbability is more deserving of a monument than a mention in a simple article, but I've got bills to pay, homie. We'll settle for some recognition for now.

Despite having the aged Johnson and the previously ineffective Andre Ellington start 11 of 16 games this year, the Cardinals still managed to finish eighth in Adjusted Rushing NEP per play. Part of that is due to the work that David Johnson did late in the year, but they also had respectable marks early on.

The thing to love about the Cardinals is their balance. The younger Johnson finished the year ranked in the top 10 in Rushing Success Rate in runs to the left (4th out of 59), up the middle (9th out of 62), and to the right (5th out of 60). This probably shows that Johnson is just stupidly good, but the line is doing its part, too.

While this is a backward-looking piece, it's also worth mentioning that the Cardinals could be built for long-term success. They have used two first-round picks on offensive linemen the past three years, but both are currently serving as back-ups.

Guard Jonathan Cooper started the first nine games this year before sustaining an injury, and he has served as a reserve since. Tackle D.J. Humphries was the 24th overall pick this year, but he has been allowed to sit behind Jared Veldheer and Bobby Massie. If Cooper rebounds next year and Humphries develops, this unit -- along with David Johnson -- could be a force for the foreseeable future.

Seattle Seahawks

Most Common Starters: Russell Okung, Justin Britt, Patrick Lewis, J.R. Sweezy, Garry Gilliam

The Seahawks take a lot of flack for their pass-blocking abilities (and that criticism is justified), but there weren't many better on the ground this year.

This was another situation in which a team lost an established starter but didn't drop in production. In fact, things actually got better once Thomas Rawls took over the reins.

Rawls led all running backs with at least 20 carries this year in Rushing Success Rate both up the middle and on runs to the right. His Success Rate was 0.545 to both directions, while the league averages were 0.387 and 0.376 respectively. He good, fam.

Does this actually indicate success on the part of the offensive line, or is Rawls just out of his mind? Both are possible, but I'd lean toward the former. Marshawn Lynch finished 12th in Rushing Success Rate on runs up the middle and 11th in Rushing NEP per carry. With his age and the injuries he dealt with, he's likely not doing that behind a group that's struggling.

All of this will set up for an interesting matchup when Lynch returns for the wild card round of the playoffs. Earlier this year, the Minnesota Vikings limited Rawls to a 0.333 Rushing Success Rate on runs to the middle and right, and that was with some of their core defensive players battling injuries. If Lynch can't regain full stride, that could complicate things for the Seattle offense, despite their dominance on the ground during the regular season.

Pittsburgh Steelers

Most Common Starters: Alejandro Villanueva, Ramon Foster, Cody Wallace, David DeCastro, Marcus Gilbert

The same concept that applied with Chris Johnson applies to DeAngelo Williams: old running backs don't magically come back to life. They're going to need some help getting there, and the Steelers provided Williams exactly that this year.

Williams finished the year third in Rushing NEP per carry of the backs with at least 100 carries. The only players ahead of him were the aforementioned rookies David Johnson and Thomas Rawls, both nearly a decade younger than Williams. Who needs youth when you've got fantastic hair and a Bane mask?.

Further validation that the offensive line deserves credit is that Le'Veon Bell finished sixth in Rushing NEP per carry. He may not have had a long run of health, but he was effective when he was there. These guys helped push the Steelers to a fourth-place finish in Adjusted Rushing NEP per play.

The most impressive portion of the Steelers' line this year would likely be the interior. Even though the team lost center Maurkice Pouncey for the year before he even saw a snap, Williams finished fifth in Rushing NEP per carry and eighth in Rushing Success Rate in runs up the middle. He was ninth in Rushing Success Rate to the right, and Bell was second in Rushing NEP per carry to the left, but solid success in the middle without your starting center is exceptional.

Another interesting aspect of the success up front is that the Steelers have done a nice job of finding cheap talent. Although David DeCastro was a first-round pick and Marcus Gilbert was a second rounder, both Ramon Foster and Alejandro Villanueva signed with the team in previous years as undrafted free agents. If Pouncey comes back and they can resign left tackle Kelvin Beachum (out with a torn ACL), this team could have some saucy depth in 2016.