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RENTON – The Seahawks rode the best defense in the NFL last season to their first Super Bowl title.

En route to a 13-3 record, Seattle allowed the fewest points (14.4) and yards (273.6) in the NFL (both numbers were team records) and forced a league-high 39 turnovers.

Then came the coup de grace, a 43-8 Super Bowl put-down of a Denver team that had shattered NFL offensive records (notably, scoring 606 points during the regular season, most in league history).

As Seattle prepares to defend that Super Bowl title, it seemed a refresher on exactly what the Seahawks do defensively was in order. Call it Seahawks Defense 101.

Second-year defensive coordinator Dan Quinn — a rising star who many think will be a head coach next year — is happy to oblige the request for a crash course.

“I think it’s important’’ fans have a better understanding of what they are seeing, he says.

The beginning

Like all NFL teams, the Seahawks run a variety of defenses out of a number of formations based on game situation and the scheme and tendencies of the opponent.

But the core of Seattle’s defense is what is generally called a “4-3 Under’’ front, using four defensive linemen and three linebackers. Under means the four linemen are typically aligned away from the offense’s strong side (where the tight end lines up) with a linebacker stationed on the line of scrimmage on the strong side.

The secondary, meanwhile, relies heavily on what is called “Cover Three” or three-deep zone — three defensive backs splitting coverage into three sections.

Essentially, the cornerbacks cover the sides of the field outside the hash marks with free safety Earl Thomas responsible for the area between the hash marks (this has the advantage of allowing strong safety Kam Chancellor to play closer to the line of scrimmage).

Seattle uses many tweaks and variations. But the basic philosophy — specifically, the 4-3 Under front — has been with coach Pete Carroll since a stint as a graduate assistant at Arkansas in 1977 under defensive coordinator Monte Kiffin.

Carroll says he doesn’t remember any Eureka! moment when he decided this was the defense for him. Instead, the longer he coached it and worked with Kiffin (he was defensive coordinator at North Carolina State from 1980-82 when Kiffin was head coach), it just began to make sense.

“Everything that we do is exactly the same for as long as I can remember,’’ Carroll said recently. “We have adapted to our personnel, we have adapted to what the game calls for now. But it’s always come out of the same notebook that basically started back in the day in Arkansas.’’

Defensive line

Up front, the Seahawks try to get the best of both worlds.

While Seattle uses a base 4-3, it also incorporates many elements of the 3-4.

As Quinn puts it, “We happen to have lots of 3-4 looks, but we are a 4-3 team.’’

The Seahawks use a smaller defensive end who is primarily a pass rusher, a position the Seahawks call LEO. (The term, by the way, doesn’t really mean anything. When Carroll worked for the 49ers they had a similar position called Elephant and Carroll later changed it to LEO.)

The objective is to have three big players who can stuff the run, and faster players on the outside who can rush the passer, or at times drop back in coverage.

The front four are defined as two defensive ends (Cliff Avril, Michael Bennett are the starters) a defensive tackle (Tony McDaniel) and a nose tackle (Brandon Mebane).

Mebane lines up over the center, McDaniel between a guard and tackle on the weak side (this is also often referred to as a “three-technique tackle’’ because of the gap over which he lines up). Bennett lines up over a tackle on the strong side (or “five-technique”). Avril, meanwhile, is the LEO, lining up outside McDaniel on the weak side.

When the Seahawks know the opponent is in a passing situation, they go to their nickel defense (a term, uh, coined for its use of five defensive backs) when they often sub out one of the bigger linemen for a smaller one who might be better at rushing the passer.

“Our end and nose and tackle are our three big guys,’’ Quinn said. “So we are half 4-3, half 3-4. They have to be big enough and stout enough to play the run, and then when we go into nickel is when we move a guy like Bennett to defensive tackle or Bruce (Irvin) to a defensive end spot.’’

Seattle’s ability to adapt its defense to its personnel was evident last year in a role created for Red Bryant, who in 2010 was moved from tackle to the five-technique end spot, tasked primarily with blowing up running plays on early downs. With Bryant gone, the Seahawks figure to also use McDaniel and veteran free agent Kevin Williams in that role.

Seattle’s line typically plays what is called a one-gap technique, meaning they aggressively rush to defend the hole immediately in front of them. In a two-gap scheme, linemen often wait and decide to go one way or the other, based on the play.


As is customary in a 4-3, Seattle’s defense incorporates middle, weakside and strongside linebackers. You will often hear players and coaches refer to these positions as the Mike (middle), Will (weak side) and Sam (strong side). They are terms that originated for the ease of describing the positions — the ability to communicate simply and effectively is a key in an often chaotic sport.

The strongside linebacker, as referenced earlier, typically is aligned on the line of scrimmage, a role usually played by Irvin or Malcolm Smith.

The Sam backer has a key role in containing outside running plays while also being called on to rush the passer, or at times cover. “He has to be long enough to take on a tackle, a tight end or a back and turn the ball back and he could be a blitzer where he has enough rush skills so that he’s closer to a defensive end,’’ Quinn said.

The middle linebacker (Bobby Wagner) has the added responsibilities of calling signals and making sure everyone is aligned correctly. The weakside linebacker (K.J. Wright) lines up next to Wagner, but on the side of the field opposite the tight end (if there are two tight ends, matchups dictate who goes where). Each has to play the run but also has to be able to turn quickly and drop into man or zone pass coverage, covering the middle of the field between the hashes, which is often referred to as the “hook.’’

“Our Mike and our Will are linebackers who generally align behind the ball for us,’’ Quinn said. “They are most of the of the time inside-gap control players in the run game and … they are hook players a lot of the time in the pass game. They have to have speed, and one of the things K.J. and Bobby have is that kind of speed.’’


Unlike teams that try to align their cornerbacks to a specific personnel matchup, the Seahawks usually assign their corners to a side — Richard Sherman to the left and Byron Maxwell to the right — and cover whichever receiver is there.

The fact the Seahawks don’t go out of their way to have Sherman shadow an opponent’s best receiver is something that is occasionally used against him in the debate over which cornerback is the best in the NFL.

Quinn smiles and says, “They can deflect that back on me. Richard can go and cover whoever. He can play inside and outside if we wanted him to.’’

Quinn said keeping players primarily in one spot allows them to play better.

“The style that we play I don’t think warrants us just constantly matching up against a player,’’ he said. “Now, in certain packages we might. But I really like our system — I think they play well in it because they understand it.’’

As for the roles of the free safety (Thomas) and strong safety (Chancellor)?

Quinn: “Our strong safety is one who, more often than not, when we play our three deep, he is the one that’s down (near the line). So we blitz him some … he takes the flat, he plays the tight end man-to-man a lot.

“Our free safety is more often back, and so for us it’s middle-field player and (Thomas) has the rare ability to play that way.

“Our three-deep is important for us because our corners, they stay on top (of the receivers) so if a receiver is going that way … we have to have underneath players who (can cover), as well as a middle-field safety who can haul ass either way.’’

All the way to the Super Bowl, as it turned out.

Feeling defensive

A look at the progress of the Seattle defense under coach Pete Carroll:

Year Points allowed (NFL rank) Yards allowed (NFL rank)
2010 25.4 (25th) 368.6 (27th)
2011 19.7 (7th) 332.2 (9th)
2012 15.3 (1st) 306.2 (4th)
2013 14.4 (1st) 273.6 (1st)

Bob Condotta: 206-515-5699 or On Twitter @bcondotta