Opinion: “Aggressive” defense doesn’t just mean blitzing

Through two weeks of the 2023 NFL regular season, the Buffalo Bills’ defense has played very well. They’re fifth in the NFL in pressure percentage per Pro Football Reference (29.4%), have given up only 302 yards (sixth in the NFL), and have a passer rating against their defense of 73.2 (fifth in the league).

But one of the key words of the offseason when it came to head coach Sean McDermott taking over the defensive play calling from longtime defensive coordinator Leslie Frazier was “aggressive.” Former players under McDermott’s play calling said it. Analysts said it. Fans believed it. The defense under Sean McDermott would be more aggressive than it was under Leslie Frazier.

The Bills are third-lowest in the NFL in blitz percentage (11.8%).

The reason these two concepts can coexist is because “aggressiveness” is not synonymous with “blitzing.”

Aggressiveness, by its very nature, is the opposite of passivity. But what does a passive defensive look like? Is the only determination of passivity how often you send more than four rushers at the quarterback? The Bills are running roughly the same amount of man coverage versus zone coverage as they did a year ago, albeit with a smaller sample size (about 25% man coverage in 2022, about 30% zone coverage thus far in 2023). It’s not that.

Here are some things to keep an eye out for this year that would count towards “aggressiveness” when designing and calling an NFL defense. Two weeks in, the sample size will be such that no definitive conclusions can be drawn, but keeping watch on these types of phenomena will help us break from the idea that “aggressiveness” is defined only by the amount of times you call a blitz:

Stunts from the defensive line

Movement up front can help generate pressure without blitzing by attempting to confuse the blocking scheme. It falls under the category of “aggressiveness” because it carries with it risk: Opening up large running lanes for a QB or a draw/screen play can allow it to backfire. Doing it anyway is one mark of aggressiveness.

Rotating safeties post-snap

Disguising coverages by rotating from a two-high look into a one-high look or vice versa is a form of aggression. You are attempting to confuse the quarterback and hoping it will cause either an ill-advised throw or increase the amount of time it takes him to make a decision with the ball, allowing your rush to get home. It, like all forms of aggressiveness, comes with risk. A slow rotation can leave one or both of your safeties out of position and vulnerable to certain route concepts, allowing a big play in the passing game if your safeties can’t get from where they were at the snap to where they’re supposed to be to execute their responsibility on that play. Here’s how often the Bills have done it so far this year in relation to other NFL teams:

Depth of cushion and press coverage

Press coverage doesn’t necessarily mean that you’re playing man. As an example, a typical Cover 3 formation asks the outside cornerbacks to align seven to eight yards off the line of scrimmage. However, they can also align in a “press bail” technique where they’re mimicking a press-man technique before opening to get to their respective deep third. Like the safety rotation listed above, choosing to align in press even though your responsibility is to the deep third of the field is a sign of aggressiveness. It can help disguise the coverage, which may mean that the quarterback takes an extra split second to identify it post snap. This could lead to the pass rush being more effective or it could lead to the timing being off on a potential passing concept from the offense. It carries with it the same risk as rotating safeties: Your defender might end up out of position because they were farther away from their designed responsibility at the outset.

Trap coverages

Trap coverage, at a high level, encapsulates coverages that are designed to show the quarterback something to force a specific throw that the defense wants them to make, while allowing a defender to be there to make a play on the ball. In the example below, the defense is playing quarters to the closed side of the field (represented on the right side of the image). On the open side of the field, they’re playing what looks to be Cover 2, with a half-field safety and the weakside linebacker as a curl defender.

But it’s the technique of the outside cornerback on this side that distinguishes this from Cover 2. The quarterback believes that the outside release of the X receiver (“No. 1” on the image) will clear out that outside cornerback and unless he’s feeling frisky for a honey hole throw between the corner and the safety, he’ll take the safer underneath route (ran by “No. 2”) who already has outside leverage on the weakside curl defender.

That cornerback isn’t going to let him take the easy throw though.

That cornerback is reading the No. 2 receiver through to the quarterback and if they see an out-breaking route, they’re going to jump it in order to make a play on the ball and pass the X receiver (No. 1) off to the safety coming over the top to help them. The quarterback is expecting the outside cornerback to continue to sink along the sideline to protect against a corner route from the No. 2 receiver and to allow the quarterback to take the shorter route over the deeper one. Matt Bowen does an excellent job of explaining it in depth here.

Trap coverages are a form of defensive aggressiveness as well. They represent taking a risk in trying to bait the quarterback into a specific throw (the one outlined above is only one example) and, in doing so, they open up other areas of the field to be exploited. Trap coverages often result in two players occupying a similar area of the field, which leaves one less defender in coverage in a more open part of the field.

This is not an exhaustive list of defensive concepts that would count as “aggressiveness,” but it’s a nice primer as we keep an eye on the differences between Sean McDermott’s defense and Leslie Frazier’s. Take note of it beforehand, look for it on Sundays, and we’ll see if this 2023 version is truly more aggressive than the last.

...and that’s the way the cookie crumbles. I’m Bruce Nolan with Buffalo Rumblings. You can find me on Twitter and Instagram @BruceExclusive and look for new episodes of “The Bruce Exclusive” every Thursday on the Buffalo Rumblings podcast network!