NFL Offense Is Dead — But It’s Unlikely Two-High Coverage Is The Guilty Party

It’s nearly November, and NFL offenses nonetheless can’t discover the top zone. That will not sound terribly stunning to anybody who’s watched the Denver Broncos play three ugly, nationally televised video games within the season’s first six weeks, however the league’s offensive woes go far past Russell Wilson and Nathaniel Hackett. Groups are collectively averaging fewer than 22 factors per recreation by means of six weeks, a development that — if it holds — would make 2022 the NFL’s lowest-scoring season since earlier than Apple launched the iPad and Girl Gaga wore her meat gown to the MTV Video Music Awards.

There isn’t any scarcity of theories as to why scoring is down, however one of many extra outstanding concepts has to do with the NFL’s continuous shift towards “two-high” security defenses, that are designed to cease the move. Because the title implies, two-high defenses hold two defensive backs downfield to guard towards deeper throws. This contrasts with the “single-high” security protection popularized by the Seattle Seahawks’ Legion of Growth within the early 2010s. Robust security Kam Chancellor and the remainder of the Hawks secondary performed a scheme that was designed to assist defend towards the run by dropping an additional defender down into the “field” close to the road of scrimmage, clogging up gaps and operating lanes.

Two-high defenses take the other strategy, with defenders taking part in zone to remove the intermediate and deep passing recreation whereas attempting to drive the opposing offense to throw brief passes and march methodically down the sphere. Since passing is extra environment friendly than operating the ball, two-high coverages are making it more durable to move the soccer, thus dragging down scoring leaguewide. 

Or a minimum of, that’s the idea.

As explanations go, it’s not a nasty one. There’s some first rate proof to help the two-high speculation: Defenses have been taking part in increasingly two-high snaps in current seasons, and the development is holding even on early downs, when groups sometimes put a robust emphasis on stopping the run. 

Thus far in 2022, the speed of two-high security protection deployed on first and second down is 34.2 p.c — up 9.1 share factors from 2016.¹ In the meantime, single-high coverages have fallen out of trend barely, dropping from 56.2 p.c on early downs in 2016 to 52.7 p.c this yr.

If two-high is efficient, we should always anticipate offenses to must adapt, and that seems to be taking place. NFL quarterbacks have responded to the shift in defensive technique not by throwing the ball much less total (passing makes an attempt per recreation are roughly the identical as years previous), however by throwing the ball downfield much less. After hovering round a mean depth of goal of 8.5 yards from 2006-14, quarterbacks throughout the league have begun to take the checkdown extra usually. The variety of designed brief performs, like screens and fast outs, has held comparatively regular, however thus far this yr, the typical move try traveled almost a yard much less by means of the air (7.7) than the 2006-14 common.²

Nonetheless, a decrease common depth of goal in response to two-high seems isn’t ironclad proof for the protection scheme’s effectiveness. In any case, the typical move when it comes to air yards has been dropping since 2016, and 2020 was the highest-scoring season in NFL historical past. As an alternative, a greater piece of proof is that passing towards two-high protection has had a destructive anticipated worth this yr. An try towards that protection is price destructive 0.005 EPA per play thus far this season, down from constructive 0.05 EPA per play throughout 2016-21. 

On its face, that looks like a big drop. However is a six-game pattern sufficient to say for certain?

To learn how this season compares to the earlier six seasons, I randomly selected six weeks³ of performs towards two-high coverages and did some bootstrapping to calculate the EPA per play. I prefer to think about this as if we put six weeks’ price of performs in a hat: After we attain within the hat and take a handful of performs from these six weeks and calculate the typical EPA per play, we throw the performs again within the hat after we’re carried out.

I did this (nicely, let’s be trustworthy, the pc did) 500 occasions⁴ with the hat filled with performs from these six weeks — sufficient to provide us a strong concept in regards to the vary of outcomes for EPA per play for that six-game interval. Then I chosen one other six weeks at random and repeated the process, taking a handful of performs 500 occasions from that new six-week pattern within the hat and determining the typical EPA per play for every handful. All instructed, we calculated EPA per play 500 occasions in every of fifty totally different six-week groupings for the final six seasons (2016-21), giving us 150,000 educated guesses about what the typical EPA per play might find yourself being in any six-game interval.

Primarily based on the outcomes, 2022 isn’t significantly particular. It seems that whereas -0.005 EPA per play towards two-high protection is decrease than what we’d anticipate, it’s not terribly low. Most years, we actually shouldn’t be too shocked to see a six-game stretch by which offenses do about this poorly towards defenses with two deep safeties.

This end result is smart to my nerd mind specifically. Yearly, bizarre statistical anomalies occur in comparatively small samples — however they don’t essentially imply something, even in the event you can assemble a compelling narrative round them. 

And this yr’s narrative of alternative isn’t with out some weaknesses anyway, as two-high coverages definitely aren’t stopping the league’s prime quarterbacks from placing factors on the board. Via six video games of the season, the highest offenses within the NFL by EPA per play are precisely what you would possibly anticipate: The Kansas Metropolis Chiefs, Buffalo Payments, Philadelphia Eagles and Baltimore Ravens. Josh Allen and Patrick Mahomes are tied for the league lead in passing touchdowns at 17, and Lamar Jackson is third with 13 TD tosses — and all three are above league common this season when it comes to variety of dropbacks towards two-high protection.

People are likely to focus quite a lot of consideration on endpoints, and we love discovering patterns (even when they may not exist). The primary few video games of the NFL season are an ideal laboratory for each of those quirks to thrive. This isn’t to say that there’s no advantage to the concept passing has been negatively impacted by two-high coverages. Each issues will be true: It’s potential that defenses have abruptly discovered the important thing to throttling passing — however it’s additionally potential that individuals are simply out right here speaking mad splits. 

Holly Fuong contributed analysis.

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