In his first season with the Vikings, head coach Mike Zimmer transformed one of the NFL’s worst defenses into a top-half-of-the-league unit. They went from allowing 30 points and nearly 400 yards per game in 2013 (32nd and 31st in the NFL) to allowing 21.4 points and 344.7 yards per game last season (11th and 14th in the NFL). With the talent they have and with Zimmer’s guidance, there’s no reason the Vikings can’t become a top-tier defensive unit in 2015.

Zimmer’s scheme doesn’t make much easy for opposing offenses, as he likes to move defenders around pre and post-snap in order to disguise pressures and coverage. The biggest staple of his 4-3 scheme, though, is his double-A-gap pressure looks.

Double-A-gap pressure creates lots of problems for pass protection schemes. The reason for this is because it brings, or at least threatens, immediate inside pressure on the quarterback. Blockers have to adjust and honor the threat because quick pressure up the middle will thwart almost any pass play. Additionally, the look almost always creates at least one favorable matchup for the defense.

Here is the prototypical double-A-gap pressure look. You can see two linebackers aligned on both sides of the center in both A-gaps.

We’ve seen teams try to protect against this in several ways. Sometimes, the offensive line will squeeze towards the middle, meaning the center and guard (normally to the side of a blocking tight end) will take the two linebackers. The problem here is that the tackle to that side has to then take the defensive tackle. This leaves a defensive end on a tight end, which is a mismatch in favor of the defense.

Another way teams protect against double-A-gap pressure is to have their running back responsible for one of the A-gap linebackers inside. This is what occurs in a man-to-man protection scheme. The man protection scheme intends to give the offense the best possible matchups. It provides for a big-on-big protection, meaning the offense’s biggest players (the offensive line) are responsible for the defense’s biggest players (the 4 defensive linemen) and whoever they identify as the “mike” linebacker.

Against double-A-gap pressure with this protection, the offense identifies one of the linebackers as the “mike,” who the center is responsible for. The running back is then responsible for the other linebacker inside. This is exactly what happened on the play below. The offense here identified Chad Greenway, #52 as the “mike.” He was the center’s man. Linebacker #55 Anthony Barr was then the running back’s man. You can see all of the matchups below.

On paper, the potential pressure is accounted for. However, at the snap Greenway initially dropped out and Barr blitzed. As you can see below, this left the center blocking no one and looking for work, while the running back was left to deal with the biggest threat inside.

Barr had a 40-pound advantage on the running back here. And while this is technically a better matchup for the offense than a running back on a defensive end, it’s still a problem for the offense because the running back has to stand up the linebacker right in front of the quarterback. He doesn’t have the option of pushing him around the pocket. Here, he was knocked aside easily for the sack.

Zimmer’s scheme put his players in a better position to wreak havoc on the opposing quarterback in 2014. While they ended up with the same amount of sacks as the year before (41), their pressure was more frequent, as they faced 114 fewer pass attempts.

The Vikings have good talent at all levels of their defense, which makes it tough not to be optimistic about their chances in 2015. They have athletic pass rushers up front in defensive end Everson Griffen and defensive tackle Sharrif Floyd. They have young talent at linebacker in Anthony Barr and rookie 2nd-round pick Eric Kendricks. In the secondary, Xavier Rhodes has shown the ability to be a reliable cover man in 1-on-1 situations. The addition of cornerback Trae Waynes (11th overall pick in 2015) should help a pass defense that asks its corners to lock up in 1-on-1 coverage often, even when playing zone. At safety, they have a smart and reliable player in Harrison Smith. Smith possesses good instincts, covers ground in a hurry against the pass, and comes up aggressively in the running game.

There is plenty of room for the Vikings defense to improve, especially when it comes to defending the run. However, when you combine their young talent with Zimmer’s scheme, you get a defense that has a legitimate opportunity to grow into one of the league’s best in 2015.