The revolution is coming.
After a decade of living in a Cover 3 world, change is inevitable. As offenses start to figure out how to consistently beat the defense that most of the league is playing, defenses will have no choice but to adjust.
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In an ideal world, the evolution of defense will be toward a purely man-coverage scheme — our guys against your guys. Though that's not always the best practice when your guys can't stick to their guys, and that has been true for however long the forward pass has been around.
Defenses have always needed a zone counterpart to their man-coverage schemes. The league went from the Cover 2/Tampa 2 defenses of the 2000s to the Cover 3 defenses of the 2010s, and now we might be on the precipice of the “Quarters” revolution in the NFL.
College football has unleashed the quarters revolution in response to the spread effect for almost two decades now, but it hasn't hit the NFL level at quite the extent.
Just in Big 12 conference games over the last two seasons, defenses ran quarters on 36% of passing snaps on first and second downs. You would have thought that number would have been higher in the 2005-15 period, as the Big 12 was popular for its quarters defense, but the conference has actually been at the forefront of shifting away from quarters in recent years.
Still, that 36% number is much higher than the NFL's 19% of snaps in quarters coverage on early downs over the last six seasons. The lowest number of snaps in quarters came in 2015 (17.7%), while the highest over those six years was in 2016 (20.2%). There has neither been a big fluctuation nor a year-by-year increase.
While the league hasn't shown an incredible increase in usage over the past six seasons — I believe we would see a bigger increase if we had charting data pre-2014 — some individual teams have shown more quarters than others. In 2019, the Raiders, Vikings and Texans played over 30% of their defensive snaps in quarters on early downs, while Cover 3 holdovers such as the Falcons (via Dan Quinn's time in Seattle) and Cowboys (via Kris Richard's time in Seattle) make up the bottom two teams in usage.
We use early downs here because third-down coverages can get funky sometimes, and we want to see what teams are up to when they can't just sell out against the pass and have to worry about a run play being called.
I've previously written about how teams should be playing more two-high zone coverages because individual teams do about as well stopping the run in two-high as they do in single-high. This article was about how defenses can stop the run with the extra box defender that single-high defenses afford. For this piece, however, we'll look at how NFL teams play quarters in the passing game and how it will have to evolve a bit to become more robust for increased usage.