The Tangible Value of Sacks: Team Analysis

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June 16, 2017
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June 19, 2017

The Tangible Value of Sacks: Team Analysis

Derrik Klassen

Last week I did an overview of the concept that sacks kill offensive drives. The piece covered when and how often offenses were being stalled due to surrendering sacks. Now, I’m going to present team-by-team numbers to give an idea of which teams can and cannot salvage offense after being sacked, as well as which defenses stifle offenses after registering a sack.

All data comes via Pro Football Reference’s ‘drive finder’ feature.

Due to some disagreements between the ‘drive finder’ feature, NFL Game Rewind, and official sack totals, a handful of teams have one more or one fewer sacks than their official number. Regardless, the idea and conversion rates hold true, and the total still came out to 1,118 sacks.

Below is a chart of how often each NFL offense converted first downs after being sacked on a given drive. Green/red indicators highlight which teams were 5% above or below the league-average 16.01% conversion rate.

An equal amount of teams were above average as they were teams below average. Eight teams marked 5% above average, eight teams marked 5% below average, and sixteen teams were within 5% of the league average. That distribution is as equal and well-rounded as it could possibly be.

Atlanta, Buffalo, and New England are unsurprising above-average teams. All three teams ranked top ten in Offensive DVOA last season and they each employ quarterbacks that have the skill set to overcome tough down-and-distance situations. Buffalo was especially aided by Tyrod Taylor’s athletic ability, a trait that boosted Buffalo to the highest post-sack conversion rate in the league.

Arizona and Detroit are not necessarily surprising, but they aren’t teams I would have suspected to place above average. In Arizona’s case, the downfield tactics of Bruce Arians and Carson Palmer lends to an offense that can dig their way out of long second or third down situations. Detroit, on the other hand, has Matthew Stafford, a daring, strong-armed quarterback who can extend plays and fire bullets from any platform. Despite a generally conservative offense, Stafford’s playmaking ability allows Detroit some cushion to give up sacks.

Cleveland, Denver, and Philadelphia are shocking above average teams. Cleveland’s spot in the green could be more a product of having so many opportunities to convert post-sack that luck played to their favor, especially considering they only made the mark by one conversion. Even considering their high conversion rate, they still had nine more drives killed via sack than the next closest team (Los Angeles Rams). For Denver, the answer could be their skill talent. The Broncos have an above average receiving corps that has the potential for big plays. Given the willingness to attack tight windows (albeit, not accurately) that Trevor Siemian showed last season, it could be that Denver’s skill players consistently came through when they needed to. Lastly, Philadelphia is an odd one. Carson Wentz has the arm and mobility to be a playmaker, so that very well could be the simple answer here. That being said, Wentz’s accuracy is erratic and his receiving corps was subpar, so it’s surprising to see those two things come together to create an above average conversion rate.

On the flip side, many of the poor converting teams make perfect sense. Given their quarterbacks, whether it be their overall poor play or conservative nature, it’s not a marvel that Baltimore, Chicago, Houston, Kansas City, and Minnesota scored below average. Baltimore, Chicago, and Houston dealt with poor quarterback play, while Kansas City and Minnesota rolled out quarterbacks who are generally averse to taking the risks that would be needed to convert tough down-and-distance situations.

Carolina and Oakland being subpar despite athletic, strong-armed quarterbacks leading the offense is shocking at first glance. In the case of Carolina, the complete lack of offensive creativity and skill talent is surely the culprit, while Oakland simply didn’t face enough sack situations for them to rack up conversions. Poor rate be damned, Oakland still had fewer drives killed via sack than any other team.

Miami and NYG are the two that aren’t necessarily surprising, but wouldn’t have been teams I guessed to land in the red. Miami, though their pass catchers are lackluster, have an athletic, daring quarterback in Ryan Tannehill. He isn’t a special quarterback, but his playmaking should have resulted in a few more conversions. For NYG, the problem had to be the offensive line and lack of running game, in addition to a dull offensive structure. Once NYG was backed up, they didn’t have the creativity to scheme open yards or the flexibility to run the ball to catch the defense sleeping. Odell Beckham Jr. and Sterling Shepard were one hell of a receiver duo, but constant iso routes can only do so much when the offense is behind the chains.

Now, let’s dig into the other side of the equation. Below is a chart of how often NFL defenses halted offenses after recording a sack.  Green/red indicators highlight which teams were 5% above or below the league-average 83.99% stop rate.

Fewer teams placed above or below average as defensive stoppers than they did as offensive converters. Whereas they were eight teams each above and below average for offensive conversions, only five defenses ranked above average as defensive stoppers and six teams ranked below average.

Denver, Houston, and Philadelphia as above average defenses shouldn’t be a shock to anyone. They each ranked top seven in Defensive DVOA. Additionally, they all have good-to-great pass rushing units that could generate pressure after creating sacks on first or second down, thus making defensive stops easier on the back seven defenders.

Green Bay and NYJ are a bit more perplexing. Both defenses were average-to-below average on the whole, yet they still managed to lock offenses down after generating a sack. The answer for both is likely their propensity for blitzing and getting cute with such blitzes. With offenses playing behind the chains, well crafted blitzes can be tricky to deal with and it’s possible that each team’s blitz packages were too much for offenses to overcome. That being said, the Jets didn’t have the same edge rushing talent that Green Bay did, so it’s more surprising for them to have been able to pull this feat off.

Minnesota and Pittsburgh don’t make much sense as poor defensive stoppers. Minnesota fell off as a unit as the season went on, but they still played fairly well all year and have Pro Bowl talent at every position. How they failed to be even average defensive stoppers after getting sacks is tough to pin down. Pittsburgh, while a little less talented, primarily on the back end, still had an overall good defensive unit that generated 38 sacks, tied for ninth-best in the league. With a good front seven and a functional secondary, the Steelers, in theory, are a better defensive stopping team than the numbers indicate.

Chicago, Miami, and Washington are all below average defensive units who reinforced that issue with their poor defensive stop rating. While all three teams had adequate pass rushes, Chicago and Miami had poor run defenses and average secondaries, giving offenses enough wiggle room to get back to the sticks. Washington, on the other hand, was bad in both aspects of defense. Their run defense was poor and their secondary was a wasteland outside of Josh Norman. Washington’s vulnerability was not unexpected.

Los Angeles is a tricky one. The defense ranks well per DVOA, but it was a “fake good” defense that was consistently aided by offenses reining back because the Rams offense couldn’t score. Considering the poor talent across the board in the back seven and the middling coaching, it makes sense for the Rams to have fallen short here.

A handful of teams were either above average or below average on both sides of the ball. Only Denver and Philadelphia notched above average on both sides of the ball. Defensively, those two are no-brainers, but as stated before, their offensive post-sack success is a head-scratcher. Conversely, Chicago, Miami, and Minnesota came in below average on offense and on defense. Chicago wasn’t a surprise on either side of the ball, Miami was a wish-wash team on both sides who likely faced some bad luck to end up below average on both sides, and Minnesota was an oddly poor defensive stopping unit paired with a known lackluster offense.

Below is a chart putting each team in their respective categories.