The Vikings defense is dominant on third down.

It’s well-known that the defense is the best third-down unit in 2017, but it’s important to note that there hasn’t been a better third-down defense in the past 27 years — and we’re limited to that number only because we don’t have data that goes back further than 1991. The 2017 Vikings have only allowed opponents to convert 25.3 percent of third downs into a new set of downs. The next best defense, the 1999 Miami Dolphins, allowed opponents to convert 26.1 percent of the time.

It’s not close; the 2017 Vikings are in a class of their own, even when compared to the ten best teams of the past 27 years.

Team Year Third Down % Minnesota Vikings 2017 25.3% Miami Dolphins 1999 26.1% Arizona Cardinals 1994 26.5% Seattle Seahawks 1992 26.6% Oakland Raiders 1998 26.7% Kansas City Chiefs 1999 27.2% Dallas Cowboys 1999 28.5% Pittsburgh Steelers 1994 28.6% Pittsburgh Steelers 1999 28.7% Tennessee Titans 2003 28.8%

One interesting thing to note about that list is the fact that no team in the past decade ends up in that top ten list above. Four teams from 1999 and two from 1994 show up. It’s important then to adjust for the offensive league environment surrounding each team. Once we do that… the 2017 Vikings jump out way ahead.

Team Year Season-Adjusted Third Down% Minnesota Vikings 2017 24.8% Oakland Raiders 1998 26.8% Seattle Seahawks 1992 27.7% Arizona Cardinals 1994 27.8% Houston Texans 2015 27.8% Denver Broncos 2012 28.1% Atlanta Falcons 2005 28.1% Tennessee Titans 2003 28.5% Kansas City Chiefs 2007 28.6% Indianapolis Colts 1993 29.0%

This dominance leaps off the page when looking at all defenses since 1991 (click for a larger version):

One can just look at the left-most portion of the graph to compare the Vikings to all the most dominant defenses since 1991:

There is no defense that is even close to the Vikings once adjusted for year.

In fact, the Vikings have been so good on third down that they’ve only played one game this year where an opponent converted more than league average — 38.5 percent; the Carolina Panthers converted a disappointing 40 percent of their third downs against the Vikings in week 14.

Only four games were even above the average of the second-best defense on third down — the Philadelphia Eagles’ 32 percent.

In the Vikings’ biggest loss, one to the Pittsburgh Steelers, the Vikings only allowed the offense to convert 23.1 percent of their third-down attempts.

Knowing that the 2017 Minnesota Vikings have possibly the greatest third-down defense in NFL history, how exactly do the Vikings do it?

Part of it is their excellence on first down. They’re seventh in the NFL in yards allowed on first and 10 and as a result, they create favorable third-down situations. That allows them to play 40.7 percent of their third downs in the 7-to-12-yard range, which is the third-most in the league.

But that’s obviously not the whole story; the two teams that rank above them in third-and-long encounter rate — the New York Jets and Miami Dolphins — only rank 12th and 11th in overall third down conversion defense.

The Vikings really seem to be doing special things on third down specifically, not just winning on the prior downs. They rank third in third-and-short (with 0-3 yards to go) defense, first in third-and-medium (4-6 yards to go) and first in third-and-long (7-12 yards to go).

Scheme

Their third-down snaps throughout the season show a variety of approaches, tailored to the specific offense they’re playing against.

Much has been made of the “Double-A Gap Blitz” look that Zimmer has helped establish as part of the national football parlance, but this year, the Vikings have been using that look less and less. Sometimes, they will use a look in the same family, like a package that overwhelms the guards with linebackers instead of the center, but they’ve sometimes avoided it altogether in favor of other looks.

For example, they played a fair bit of Cover-4 without mugging a gap against the Atlanta Falcons on third and long, but played a hefty chunk of Cover-2 shells against the Detroit Lions. The Steelers, on the other hand, saw Cover-1 and a good mix of blitz-friendly looks, especially with Harrison Smith as an overhang defender off to the side.

Some of this is dictated by the opponent’s formation, but sometimes, the Vikings were willing to stick to a coverage shell against a team regardless of personnel and formation. Atlanta deployed a lot of 2×2 and 3×1 sets — formations where eligible receivers are either split evenly with two on each side of the line (2×2) or unevenly, with three on one side of the field and a fourth on the other (3×1), and the Vikings were willing to deploy a Cover-4 shells, where both safeties and both outside corners cover the deep back end of the field.

The Vikings didn’t blitz the Falcons too much on third and long as a result, and knew that if they dropped enough players into coverage that their front four would get pressure in time to force a bad throw.

The Vikings followed a much different strategy against the Steelers, choosing man coverage looks to enable blitzes. The defense below isn’t quite a Cover-1 man, but it does demonstrate their willingness to put five rushers on five blockers and once again force a quick throw.

As a side note, look at how absurd Smith’s assignment is. He’s at the bottom of the screen and follows the drag route across the formation until he picks up the slot corner’s assignment heading upfield. The slot corner, meanwhile, takes on the underneath route.

Against the Lions, the Vikings would constantly show blitz, often by mugging up both linebackers in the A gap, though sometimes moving them and the defensive tackles around. They didn’t blitz often, and when those linebackers dropped back, Stafford always took the difficult throw to the sideline rather than test the middle of the field.

The gallery below (click the thumbnail to play the GIF) shows a number of instances on third down where the Vikings showed blitz and dropped linebackers into coverage. Each time, Stafford threw it to the outside.

There’s even an instance where an open underneath receiver who doesn’t get targeted as Stafford looks for an outside receiver while getting sacked.

Because of this, the Vikings cornerbacks know that they can largely play with inside leverage while pushing receivers to the sideline. They can essentially play Cover-2 in order to facilitate that push to the outside — which is what they did on five of seven third-and-long situations with the Lions — while leaving the underneath vacated, because Stafford won’t attack it.

The Vikings ability to play any coverage with their personnel, combined with their fantastic situational film study, allows them to exploit tendencies in their opponents without sacrificing anything in terms of familiarity or comfort with their own scheme.

They’ve played a number of man, zone and mixed coverages with no dropoff in performance. Not only that, their disguised coverages can look a good deal more complicated than traditional traps, and the coverage rules aren’t always easy to figure out.

Personnel

This isn’t possible without talented players. The Vikings may have the best defensive roster person-for-person in the NFL, and that’s because of their combination of technique, athleticism and intelligence.

Not many defenses can put a linebacker one-on-one with Tevin Coleman, who ran a 4.40 40-yard-dash at his pro day, but Anthony Barr can. Despite checking in at 50 pounds heavier than Coleman, he ran a 4.41 at his own pro day at UCLA.

The play below represents a failure — Coleman converts on fourth and 2 — but demonstrates the wild speed that Barr can play with to take down one of the faster running backs in the NFL. The fact that he could run down Coleman after dealing with, essentially, a pick as well as a few yards to catch up, is impressive.

There’s also the well-known fumble he caused in 2014 against the very same player.

Around them are players like Smith, who rightfully earned an All-Pro nod at safety for his ability to do anything anyone asks of him. His persistent threat on third down to either intercept a pass or sack the quarterback makes him a vital player for defenses to key in on, but a difficult one to plan for.

The Vikings have, in Smith, a stick of dynamite that they roll on to the field on third downs to see how the offense responds.

Against the Packers, he lined up as a linebacker and moved to the edge in order to stay on top of Lance Kendricks. It turned into an interception.

Against the Bears, the Vikings designed a blitz where Smith and Danielle Hunter combined to force pressure and an incompletion through solid coverage. The unusual thing is, Smith caused the pressure and Hunter was in coverage.

That controlled chaos can create devastating combinations with any other player on the team. The sheer athleticism of a player like Hunter, Everson Griffen or even Brian Robison, allow them to be credible threats in coverage, even downfield. At the same time, Smith’s play strength allows him to replace one of them as a pass rusher and still create havoc.

The Vikings personnel on defense showcase a number of strengths and very few weaknesses — characterized only as weaknesses in a relative sense; on most teams, the type of roles that players like Mackensie Alexander and Andrew Sendejo fill would be more than adequate and would even provide an upgrade for a good chunk of the NFL. For the Vikings, their status as weakest-links-by-default does more to emphasize how tough it is to play matchups against Minnesota than anything else.

The unique blend of athletes who play well in a variety of situations and roles along with phenomenal playcalling from the coaching staff would be enough to craft a good defense, but on third down the Vikings are great. The third ingredient has quite a bit to do with the intelligence of the players on the field.

Smith often adjusts the secondary to change up their coverage or get them into proper run fits. That in itself takes quite a bit of capability. But for players like Smith, the key isn’t just knowing what everybody’s job should be, it’s intuitively understanding how those jobs interact with each other and how to play when something might fall apart or goes in a different direction.

Below, Smith begins adjusting Alexander’s assignment but can’t finish by the time the play starts. His immediate reaction is to take over the role in order to win the play.

https://twitter.com/Luke_Spinman/status/950273689911574529

The pick-six below also demonstrates how in-tune the Vikings are with each other and their ability to adapt on the fly. On third down, the Bengals motion out of their look with under 15 seconds left on the play clock. Because there’s no time left on the clock, the helmet radios are off and the Vikings players have to adjust on the fly.

Their communication in a loud stadium puts them into a different look and creates different roles for each player on the defense. As the team settles in, the snap releases the receivers into their routes and Kendricks works to gain depth and leverage.

Kendricks knows that he has to keep moving his zone to account for Brandon LaFell crossing his face as well as the fact that he also needs to stay inside of Alex Erickson’s route because Newman has the outside.

This puts him in perfect position to pounce on the small throwing lane and grab the pick. His instincts allow him to put the ball into the end zone.

The Vikings are smart, fast and technically sound and the roster has very few weaknesses. They’re coached by a fantastic play caller and the team clearly does its homework.

Minnesota’s third-down dominance is something we haven’t seen in the NFL in a long time, possibly ever. And it could be what drives the Vikings to win the first Super Bowl in franchise history.