LINKEDINCOMMENTMORE

Maybe the strength of Mike Zimmer’s defense isn’t so much his Double-A gap blitz scheme, but Zimmer himself.

Zimmer has turned around the Minnesota Vikings’ defense in only two seasons: In 2013, the year before he became coach, the Vikings finished last in the NFL in points allowed and No. 31 in yards allowed. They improved dramatically last year, in his first season, to Nos. 8 and 14, and this season they’ve been one of the NFL’s best defenses (Nos. 2 and 9).

The distinguishing characteristic of his 4-3 scheme is the Double-A gap portion of his playbook. Every team in the NFL has Double-A gap calls, so Zimmer’s success deploying it as a defensive coordinator for three NFL teams (Cowboys, Falcons and Bengals) and now coaching the Vikings suggests he somehow teaches it better than anyone else.

And that may be true. But a high-ranking scout for a team that has played the Vikings this season thinks Zimmer’s scouting acumen is equally important.

“He understands personnel and how to attack those guys,” the scout said. “’Yeah, we’re going to hit the Double-A gap, but this (offensive lineman) is going to step this way, or this guy is a strength guy, or this guy’s a finesse blocker, or this guy’s not very tough.’ He understands the essence of personnel so when he makes those calls he knows exactly what he’s getting.”

Though there’s always a risk of making these calls too early – Ray Rhodes, after all, was the NFL’s coach of the year after his first season in Philadelphia – the early signs suggest that Zimmer is a quality head coach and that the Packers will be dealing with his defense for years to come.

And they face it Sunday at an especially bad time. The Packers’ offense has under-performed in three straight losses, and the seeds of their offensive struggles go back several weeks before that, to Week 4 at San Francisco when they scored only 17 points in a win over the 49ers.

Now they will face the league’s No. 2 scoring defense after averaging only 18.3 points the last three games against Denver, Carolina and Detroit.

Zimmer runs a standard 4-3 defense and the Double-A gap is an important part of it, though he deploys it strategically. For instance, last week against Oakland he used a true Double-A gap alignment on only six snaps, and two weeks ago against St. Louis he used it on seven snaps, though four of those were in the fourth quarter of a tight game.

Here are the basics of the Double-A gap scheme: It’s deployed on passing downs in nickel personnel. Both inside linebackers line up at the line of scrimmage, one in each “A” gap, which is the gap between the center and each guard. For the Vikings, the inside linebackers usually are rookie Eric Kendricks, a second-round pick who’s just returning this week from a rib injury, and Anthony Barr, a first-round pick in 2014 who has been playing with his left hand in a small padded cast.

Sometimes both linebackers will blitz. Sometimes one. Sometimes neither. And defensive backs can be incorporated as well. Zimmer often brings safety Harrison Smith near the line, where he sometimes blitzes on the outside and other times drops into short zone coverage.

Kendricks has four sacks, which is excellent for an inside linebacker at this point in the season. Barr has 1 1/2 and Smith one. More telling of just how effective they are in blitzes: according to Pro Football Focus’ pass-rushing grades, Smith ranks highest among all safeties in the NFL, Barr ranks highest among all 3-4 outside linebackers, and Kendricks ranks third among all inside linebackers.

“They’re all up there (at the line),” said an assistant coach with a team that has played the Vikings this season. “Who’s coming? You don’t know. It’s like a lottery pick. (Zimmer) will have a guy on the edge, he’ll have a guy on the A gap, and then you try to block the A gap and they’re bringing the guys from the outside. He does quite a bit of that stuff.”

The two linebackers pose a huge threat because they have the shortest route to the quarterback of anyone on the line. There are several ways to block them.

The line can slide one direction or the other, with each lineman blocking the most immediate player to that side. But that leaves a defensive end blocked by either the running back or tight end, which is a favorable matchup for the defense.

The line also can gap protect, which means everyone pinches to the center. But that again leaves an outside rusher to a back or tight end.

Or there’s man-to-man blocking, but a back often has to step up and take on a linebacker who has a running start up the middle.

“And they like to distract you with the Double-As and maybe bring somebody else off the edge,” said Corey Linsley, the Packers’ center. “Sometimes it’s not a distraction, it’s what they’re actually doing.”

The Packers should be well equipped to deal with the Double-A gap scheme. They have two accomplished and experienced guards in Josh Sitton (eighth-year pro) and T.J. Lang (seventh year), and a good young center in Linsley (second year).

Plus, they have one of the game’s two best quarterbacks in Aaron Rodgers, who is experienced (eighth year as a starter) and mobile.

“Green Bay is as good with those three (interior linemen) as anybody in the league,” the scout said. “The quarterback certainly, despite not having played great the past couple weeks, is obviously still one of the best in the league.”

Playing at Minnesota will make things more difficult because of the noise, though it won’t be as bad at the University of Minnesota’s outdoor TCF Bank Stadium as it would have been at the Metrodome. Also, James Starks is hit-and-miss as a pass protector, and he’s going to start at running back, though it’s unclear whether he or Eddie Lacy will get more playing time.

“Communication problems are going to be an issue,” the assistant coach said of playing the Vikings on the road.

There also can be an element of improvisation in Double-A gap blitzes. On some calls the blitz is pre-determined, but on others only one of the A-gap linebackers blitzes, and that’s based on which way the protection slides. If it slides to the defense’s left, the linebacker to the right of the center blitzes, or vice versa.

So some teams will drop their center straight back to try to confuse the blitzers, though that again means the rest of the line has to pinch, which leaves an outside rusher with a matchup against a tight end or running back.

In the end, though, this could come down to the match-up of Rodgers against the Vikings’ blitzes. And based on the lack of trust Rodgers has had for his receivers in the last three games, you have to wonder if Zimmer will test them early with Double A-gap looks to see if anything has changed this week.

"Your receivers have to be on their game as far as running hot (routes) so the quarterback can get the ball out without having a dent put on him when he throws the ball," the assistant coach said. "Third down it becomes an issue. (Zimmer) is going to get (guys) up there, he’s going to stress your protection, he’s going to get your quarterback out of a rhythm of being able to sit there and be comfortable because they’re all up there. He puts the pressure on you. If you have a guy like (Tom) Brady or Aaron and they get the ball off in rhythm, they’ll carve it up.”

— pdougher@pressgazettemedia.com and follow him on Twitter @PeteDougherty.

LINKEDINCOMMENTMORE