Run Defense By Number of Backs, 2016

by Rivers McCown

EDITOR'S NOTE: Putting this piece together, we realized we needed to re-format the table that ran in the offensive version of this essay last week. That table should be more easily readable now.

You know the deal. This is another of our stat posts breaking down information from the 2016 season.

Today we're looking at how defenses fared against the run when the offense had either one or two backs in the backfield. Is there any evidence that the trend towards smaller defenses is making running power sets easier? If so, is it isolated to just a few teams, or is it league-wide?

For the purposes of this analysis, we're measuring rushing attempts by any player who was lined up in the offensive backfield but was not at the quarterback position. Single-back formations mean one player other than the quarterback was lined up in the backfield and ran the ball; two-back or multiple-back formations mean more than one player other than the quarterback was in the backfield, and one of those players ran the ball. The numbers include direct snaps to a player who was lined up as a running back, but do not include:

• scrambles;
• quarterback keepers;
• wide receiver or tight end end-arounds or reverses;
• or "Wildcat"-style plays.

Volume Comparisons

The most interesting thing about this table is probably that the teams that had to face two-back sets the most performed poorly as a whole against them. Only three of the 11 teams that faced 100 or more two-back sets fared better against them than they did against one-back sets.

Miami had the biggest difference in favor of their play against two-back sets, which is counter-intuitive. One of the supposed weaknesses of the Miami defense is their linebacker play, and yet trying to get them to put more linebackers on the field was a bad idea last year -- at least, if you were planning on running the ball. The Dolphins also faced a large amount of two-back runs in 2015, the fourth-highest amount in the league, and had essentially no split. It's worth pointing out that a few of Miami's role players had impressive small sample-size rates last year. Defensive tackle Earl Mitchell played just 308 snaps, but finished 18th in stop rate on runs at 88 percent. Linebacker Donald Butler played 356 snaps and ranked 10th in linebacker stop rate on runs at 73 percent. (Stop rate here represents the percentage of tackles/assists that stopped a run short of our baseline for successful yardage.)

Of the teams that saw 100 or more runs from two-back sets in 2016, only two of them weren't repeaters from 2015: the Jets and the Browns. The Browns merely saw 96 two-back sets in 2015. The Jets were a more interesting story, increasing from 63 to 106. Of course, there were major personnel changes for the Jets on defense, as they lost nose tackle Damon Harrison and had massive turnover amongst their linebackers. They also simply weren't a very good team, so they were more likely to face runs in general. The Jets were still a great run defense, though, as we went over in 2015's review piece.

Of the repeaters (Miami, the Chargers, Oakland, Houston, Indianapolis, Denver, San Francisco, Tampa Bay, Jacksonville), Indianapolis stands out. They faced 121 two-back set runs in 2015 and performed 22.5% better by DVOA than they did against single-back sets. They followed that up by being 20.2% better against two-back sets than one-back sets in 2016. Don't give in to Chuck Pagano ball, folks. If there's one thing he knows how to do, it's watch an offense struggle from two-back sets.

Many teams that faced 100 or more two-back runs in 2015 didn't in 2016: Minnesota, Washington, Green Bay, Baltimore, Seattle, Chicago, Atlanta, Tennessee, and the Rams. This isn't surprising as the general trend has been away from two-back sets. Teams like Atlanta and Dallas, who set up massive game script advantages over the course of the season, also naturally faced fewer power, run-out-the-clock sets. No defense saw fewer two-back runs last year than Pittsburgh—the same team that saw the fewest two-back runs in 2015.

Efficiency Comparisons

2015's worst team defending two-back sets was Minnesota, which saw 134 two-back runs in 2015 and just 69 in 2016. (They crushed two-back sets in 2016.) The ascension of Eric Kendricks probably played a role in that.

By far the worst team was Baltimore, which is hilarious because through the first 12 weeks of the season they were on pace to have the best run defense DVOA of all-time. Against two-back sets, though, they were actually a below-average run defense. That trend holds up from 2015, as they finished 10.5% worse against two-back sets in that season. I guess this is a good place to note that the Ravens never really adequately replaced Daryl Smith. The defensive line held up well, but their edge players were poor run defenders. C.J. Mosley had especially poor numbers, with a 52 percent stop rate on 48 run plays. With Zach Orr (probably?) gone and no real inside linebacker replacement on hand, it'll be interesting to see how that plays out in 2017.

The largest fall came in Carolina, where the Panthers went from the fourth-best difference against two-back sets to the second-worst. Luke Kuechly missed six games, but that doesn't explain the entire dropoff. Thomas Davis had a surprisingly low stop rate of 57 percent on 49 runs, which ranked 67th among linebackers. Perhaps this will be the year the Panthers turn the reins over to Shaq Thompson, although Thomas still shines on pass plays.

The best team at defending two-back sets in 2015 was the Chiefs, who had a DVOA difference of 33.5% in favor of two-back runs. That regressed hard in 2016, as they were actually 1.1% worse against two-back runs. It's worth noting that they let Dontari Poe go, as great of a quarterback as he was last year.

While Indianapolis is weirdly consistent in one way, the Chargers and Raiders are frequent targets of two-back sets, and they actually deserve it. The teams finished with the second- and third-worst DVOA differences against two-back sets in 2015. In 2016, they made it all the way to fifth- and sixth-worst! Both teams have had middle linebacker revolving doors for a while, although the Chargers have definitely invested much more in that position between Manti Te'o and Denzel Perryman.