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Seahawks' New 'CLEO' Coverage, Part 1: Overview and History

During the 2021 season, the Seahawks ran a new pass coverage called "CLEO." In a four-part miniseries, Matty F. Brown explores the coverage's history, makeup and success.

Matty F. Brown

In this story:

The 2021 Seahawks ran a new pass coverage for their defense. While head coach Pete Carroll is often thought of as a conservative figure, the defensive guru and his staff devised a contemporary solution to slow quarterbacks and offenses through the air: the “CLEO” defense.

This was a middle-field open, zone-matching, nickel pass coverage that suited Seattle’s personnel and compensated for how offenses looked to move the ball against the unit. With multiple reports of Carroll desiring a more aggressive and attack-minded defense in 2022, CLEO should be here to stay in Seattle's defensive system under new defensive coordinator Clint Hurtt. This four-part series will cover CLEO's overview, 2021 application and future.

Part 1: Overview and CLEO Past 

Part 2: 2021’s Successful CLEO Application

The Seahawks, who've historically employed middle-field closed Cover 3 under Carroll, generally spent a significant amount of 2021 in middle-field open defenses.

  • SportsInfoSolutions charted them as running the fourth-highest percentage of Cover 2, Cover 4 and Cover 6 in the NFL. (Middle-field open zone coverage versus dropback passing game; excludes Red 2, screen coverage, combination coverage and goal line.)
  • TruMedia had the Seahawks in the fifth-highest percentage of middle-field open. (The coverages charted as two-man, Cover 0, Cover 1, Cover 2, Cover 3, Cover 4, Cover 6, bracket, goal line, red zone, prevent, miscellaneous and other.)

“We’ve seen certain things. We’ve seen how teams are gonna try to attack us in this defense, so we kinda know what to do,” safety Quandre Diggs described on December 15. “And then early on in the year we couldn’t really expect that because, you know, we’ve got a few different coverages that we haven’t ran previously in games.”

CLEO—the different coverage Diggs referred to—was a major contribution to the defense’s recovery to improvement as the 2021 season progressed. I first encountered the pass defense after watching nickel cornerback Ugo Amadi sprint high and inside with a slot receiver, while the outside cornerback to his side of the field stayed in the outside underneath space and Diggs worked over the top in a deep half zone. Inspired by a "WHAT THE HECK WAS THAT?!" moment akin to a UFO sighting, some high quality images revealed the CLEO term. And while Diggs did not give up the playbook, he too acknowledged CLEO’s existence. 

Linebacker Bobby Wagner explained the thinking behind the otherworldly changeup.

“Like when we were, you know, with Kam [Chancellor], [Richard Sherman], Earl [Thomas], you know, we all play Cover 3. That’s all we did was play Cover 3, nothing else,” Wagner said on October 13. “Like, we would line up and basically just say: ‘We are better than you, and we don’t care what you do.’ And then they start putting four-strong and we don’t have enough people in four-strong, so you have to adjust. And so you don’t see as, you see different versions of our defense out there where it’s Cover 3.”

In simple terms: the four-to-one-side issue Wagner mentioned essentially meant their Cover 3 looks were outnumbered four versus three to that area. Other ways of fundamentally breaking Cover 3 occurred too. Things were forced to change.

“But now there is more Cover 4 element, more Cover 2 element because they figured out the weak spot in the Cover 3 defense," Wagner continued. "So you can’t just sit there and be like, you know, 'We’re better than you,' and play Cover 3 all day because, you know, it took some time but they found some beaters in that coverage. And so it’s a cycle, you know what I mean? A lot of teams are running Cover 4 right now. And then, give it a couple of years, I feel like it might be a Cover 2 league, and then give it a couple of years, Cover 3. I mean, it’s all about cycles. Depending what cycle you’re in.”

And that’s what CLEO Is in simple terms: Cover 2 to one side and Cover 4 to the other. It fits the current cycle of popular coverage. Before looking at the 2021 application and CLEO’s deeper complexity, the etymology of the word “CLEO” proves insightful.

Monte Kiffin—the man Carroll learned defense under—has used CLEO on multiple occasions. In Kiffin’s 1998 Buccaneers playbook, CLEO is defined as: “Force No. 1 outside, and play flat area. Alert to force run.”

This matches Carroll’s own play history of CLEO. In his 2007 USC playbook, CLEO is written underneath the cornerback in a defense called “Nickel Saint.” This was a Cover 3 coverage that placed the outside corner—like Kiffin—in a hard inside cloud technique and run force. In order to accommodate this, a deep safety rolled over the top of the corner into the deep outside 1/3. 

Indeed, like Carroll and Kiffin's pasts, Seattle's version of CLEO in 2021 did have the cloud cornerback playing force, although it was more of a secondary force deal with the strong safety expected to participate more. (The second part of this miniseries will feature examples.)

On a wider level, the background of Kiffin’s overall nickel defense philosophy was visible in Seattle’s 2021 CLEO coverage.

“Our nickel defense is designed to let us cover the strong and weak side of the formation with a variety of coverages and techniques designed to maximize our coverage and minimize offensive execution,” wrote Kiffin in his 1991 Vikings playbook. 

“The S/S and F/S will line up on the passing strength side of the formation. The nickel man will line up on the weak side of all formations. The corners will basically stay at home in nickel.”

Alignment-wise, the Seahawks did not place the strong safety and free safety on the same side like Kiffin in 1991. However, Seattle did employ a similar recognition of the offense’s strength with the positioning of its defensive backs. It was just that it chose for its nickel, Amadi, to align to the field along with Diggs. If the ball was in the middle of the field, this ended up being to the passing strength. Meanwhile, safety Jamal Adams aligned away and to the short side of the field.

Where CLEO combined Cover 2 pass defense to one side and Cover 4 to the other was not a vanilla, drop-to-a-designated-area-and-vision-the-quarterback, quarter-quarter-half, Cover 6 defensive look like those we had seen in recent years from the Seahawks' defense. Instead, CLEO also joined some more aggressive, zone-matching techniques into the coverage. This was how we got the visual of Amadi sprinting high and inside the slot receiver. 

CLEO also fit the history of 2021 Seahawks defensive coordinator Ken Norton Jr., with Norton working under Jack Del Rio in the same role for the Raiders from 2015 to 2017. During this period, Norton ran similar concepts to CLEO. As Coach Vass highlighted to me, “Pack-Stuff” coverage is present in Del Rio’s coaching journey, with Del Rio learning from Marvin Lewis’ Ravens era. “Stuff” refers to the Cover 2 being played to the strength; “Pack” refers to Cover 4 to the strongside.

In fact, as Vass highlighted on Twitter, matching quarter-quarter-half pass coverages have been prevalent for some time throughout the NFL. This is Rex Ryan's 2010 Jets edition using the terms "Laser/Pack:"

Here's Jim Schwartz' "56" from his 2014 Bills defense, which incorporated similar principles:

The key difference with the Seahawks' CLEO compared to the historic NFL examples of similar coverage was that Seattle bravely played the Cover 2 element or "stuff" side to the strength. In this sense, it was half-quarter-quarter.

CLEO to 11 personnel 2x2, field left. (Image made with QwikCut.)
CLEO to 11 personnel 3x1, field left. (Image made with QwikCut.)
CLEO to 11 personnel 3x1, field left. (Image made with QwikCut.)

Furthermore, unlike Norton's Raiders days where re-routes were frustratingly absent, the Seahawks' 2021 coverage regularly achieved a collision from their outside corners, particularly the cloud/CLEO assignment. In an NFL that is rapidly officiating the re-routing of receivers out of the game, one remaining method is to have smaller corners contact pass catchers on the outside.

From a roster perspective, the over-the-top help provided by the Seahawks' half safety and quarters safety allowed the numerous cornerbacks who saw 2021 action to play aggressive with more confidence. To the half side, the cloud corner was not responsible for the deep. And to the quarters side, the quarters safety was camped in the dig-to-deep window, giving the corner some help inside when pitching his tent.

The physicality, combined with the other coverage techniques and boldness in playing the Cover 2 part to the strength, allowed Seattle to better leverage the beater route combinations it saw in 2021 and even past seasons. That’s what a tape-heavy second part of this miniseries will cover: the specific application that saw coverage success last season. The third part will then look at the future of CLEO on the 2022 Seahawks defense.

Published
Matty F. Brown
MATTY F. BROWN

Based and born in the UK, Matty has coached football for over 5 years, including stints as a scout, defensive coordinator, and Wide Receiver/DB Coach. Asides from an Xs and Os obsession, he enjoys: other sports; eating out; plus following Newcastle United. He graduated from the University of East Anglia in 2018 with a BA in Modern History.

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