The following is from the 2022 Sharp Football Preview
In this book, you’re going to read a lot about aggressiveness on offense. Often, that’s the best way forward. As spread offenses and superhuman robot quarterbacks like Patrick Mahomes and Justin Herbert entered the NFL, there was always a question about how defenses would react. The answer, in a way, was to become less aggressive.
That shouldn’t be read as “conservative” because defenses aren’t just sitting back and letting offenses attack, but across the league, there has been a scale-down on aspects we would generally consider aggressive. But these defensive strategies we’re now seeing have played into using the offense’s aggressiveness against them.
Last year in this foreword, we explored the concept of space and how offenses were getting increasingly better at manipulating it to set up big plays and create yards after the catch. What defenses are doing now is in reaction to that — limiting the space an offense has to work with.
The increase of two-high safety shells was in part to limit the explosive pass plays. (Yes, we’re going to oversimplify some concepts here… you’ve still got over 500 pages in this thing to go.) But “two-high shell” doesn’t necessarily mean “two-high coverage” 17 teams used a two-high pre-snap shell on at least 50% of snaps in 2021, per Sports Info Solutions, but zero teams used some version of a two-high coverage on over 50% of pass plays. The highest team was at 45% and 15 teams were over 40%.
Those pre-snap safety alignments are about having the flexibility to show one thing and change the look after the snap. This is also a big reason for the increase in safety value and versatility. Having safeties that can play all over the secondary allows for more deception with these rotations.
As a result of the shifting structures across the league, passing to both the intermediate level of the field (11-19 air yards) and deep (20+) produced the lowest EPA per attempt for offenses since the 2017 season.
To fight against this, offenses have gotten the ball out quicker and shorter passes have increased. The average depth of target has dropped over the past three seasons from 8.18 in 2019 to 7.79 in 2020 to 7.75 in 2021, per TruMedia. The rate of passes thrown at or behind the line of scrimmage has risen each year since at least 2013 and in 2021, 71.4% of passes were thrown within 10 yards of the line of scrimmage.
With so many passes getting thrown to that area, the defensive adjustment has been to flood more defenders into throwing lanes. That has come at the expense of blitzing aggressively.
Last season, defenses blitzed just 25.3% of the time, the lowest rate over a full season since at least 2013, per TruMedia. The biggest jump came on early downs. In 2020, defenses blitzed on 27.1% of first and second down dropbacks. In 2021, that dropped to 23.7%. Big blitzes of six rushers or more dropped from 5.1% to 3.7%.
Part of this comes from top-tier quarterbacks being too good at picking apart the blitz. During the 2021 season, there was essentially a “do not blitz” list that featured Mahomes, Herbert, Matthew Stafford, Joe Burrow, Tom Brady, and Kyler Murray. Those quarterbacks also ranked (in order) second, ninth, first, seventh, 15th, and third in EPA per dropback against the blitz. With an extra defender rushing, these quarterbacks were so good at finding the hole left in coverage that defenses mostly cut their losses in trying to manufacture pressure and instead kept more players in coverage.
League-wide, this was a growing strategy. In 2021, defenses rushed four on 69.9% of plays. That would have been a top-10 rate for a singular defense in 2020. 18 teams were above 70% in 2021. Again, this didn’t mean defenses were just being passive.
More defenses have used simulated pressures, which shows the threat of a blitz with multiple players around the line of scrimmage only to rush four, but disguising which four players is the point. This can give similar effects to a blitz by manipulating protection rules and potentially creating free rushers, but still getting seven defenders back in coverage. In fact, defenses increased their pressure rate with four-man rushes in 2021 and EPA per dropback against four-man rushes (0.00) was easily the lowest since at least 2013 (0.03 in 2017 was the next-lowest).
Teams like the Bengals took this a step further with Drop-8 coverage, which uses just a three-man rush. Though while Cincinnati got the most publicized use, the rate of the three-man rush has dropped from 7.1% in 2019 to 6.3% in 2020 to 4.6% in 2021. Only three teams rushed three on at least 10% of pass plays: the Patriots (13.1%), Giants (11.3%), and Bengals (10%) after five teams did so in 2020 and three of those did so on at least 15% of pass plays. Bill Belichick has long been the leader in rushing three, but like the four-man rush, it’s about disguising which three are coming.
After the success the Bengals had with it in the playoffs and especially against the Chiefs (they upped the rate to 16.1% in the postseason, 39.1% against Kansas City), we could see more teams work in Drop-8 coverages in 2022.
With more bodies back in coverage, the ability to rally to the ball, even when a pass is completed, can limit the effectiveness. Last season, only 53.1% of completed passes picked up a first down or touchdown. That’s, again, the lowest rate since at least 2013 and down from 55.7% in 2020. We’re seeing more empty plays when the offense still gets the completion but the space is occupied and the defense still wins.
Defenses have started to find their counter and there are replicable ways to go against the offenses that are spreading through the league. Defenses have been more adaptable to new concepts — even Pete Carroll is hiring Vic Fangio disciples to change up his defensive scheme. There are young defensive minds heading up some of these innovations and for the first time in a long time, a youth movement on that side of the ball — DeMeco Ryans in San Francisco, Aaron Glenn and Aubrey Pleasant in Detroit, Mike McDonald in Baltimore, Ejiro Evero in Denver — brings a similar enthusiasm for the future as the coaching prospects do on offense.
We’re not at the point where defenses constantly have the upper hand against offenses, but the league might currently be closer than it’s been in a while.
