Scheme Changes Coming for Vikings Defense

Mike Zimmer said during a press conference a few months ago that he was making some scheme changes on defense, indicating, “some of it is big change, some of it is minor tweaks.” Both Zimmer and co-Defensive Coordinator Andre Patterson talked about the meetings the Vikings’ defensive coaching staff had early in the off-season, and Patterson elaborated on them a little more after mini-camp:

As a defensive staff, we did a lot of work on studying different fronts, different coverages around the league, and even some in college football that people are doing to handle what offenses are doing today. It reminded me when me and Zim were in Dallas, I think it was after the 2000 season, and we had been running the same defense forever, and we got together and studied and put together the scheme that we use now. It was an off-season that was a lot of learning, a lot of us growing as coaches, and I felt that’s what happened this off-season. We spent a lot of time studying and working and evaluating different fronts and different coverages that you can use in different situations. And I think we got better as a coaching staff, and I think we came up with some things that I think are going to help our players.

Patterson also mentioned that having OTAs and Mini-Camp this year has been instrumental in working out what will work best for this group of Vikings’ defenders:

...It’s been great that we’ve had these practices, because we’ve been able to put it on film, and it’s not just the ‘theory of the board’ if you understand what I’m saying, right? You put it up on the board in the Xs and Os and it looks great, but then you get it out on the field and it doesn’t match your guys, and the talent that you have, it’s not a good thing for you to do. So, the one thing that’s been great is that we’ve been able to develop a library, you know, and pull all these things that we want to look at, and put it into a cut-up, and then we’ll go back again and re-study it and say, ‘this is good for us, this is not good for us,’ and if we didn’t have these OTA practices, we wouldn’t be able to do that. So, I think that’s exciting for us too, and we’ve been doing that throughout the process- let’s watch all these different fronts, let’s watch all these different coverages, and see how it marries together with our players.

Local Vikings’ beat reporter Courtney Cronin reported that the Vikings had been mixing in some 3-4 fronts during the off-season practices this month- something Zimmer has experimented with in the past as well. So far, he’s never really used a 3-4 front much in Minnesota, if at all. A big reason why may be that in the past, he didn’t have the full complement of defensive linemen to make it work well- but this year he does.

It’s unlikely that Zimmer will make a wholesale change to a 3-4 front, but he may incorporate some 3-4 fronts to counter particular offenses, packages, or situations. One of his complaints about his scheme last year was that it was bogging the players down with too many adjustments, requiring them to think, rather than just react and play fast. That probably applied more to the secondary than the defensive front, but players in both groups can get caught up with too many adjustments that complicate the scheme. Moreover, Zimmer said it was becoming too difficult to install all the needed adjustments for each opponent, each week, during the season.

So, I suspect the goal for Zimmer and Company schematically is to install some additional ‘set-pieces’ to address particular offenses, and which also provide some versatility to address multiple needs as well. Installing them during the off-season allows players to learn and practice their assignments and understand the scheme, so when the regular season rolls around, they’re ready to go and can play with fewer adjustments.

Let’s take a look at some possibilities.

The Bear Front

One option the Vikings haven’t used much in the past is the Bear Front, which gets its name historically from the 46 Front the ‘85 Bears used, although the actual front and formation is no longer the same. The modern version is a 3-4 based front, with three big defensive tackles covering the center and guards, and the two OLB/edge rushers crashing in from outside the tackles.

Using current Vikings’ personnel in the illustration above, Michael Pierce (#97) is the two-gapping nose tackle, covering both ‘A’ gaps between the center and guards. The other two defensive tackles (or ends in a 3-4 front), in this case Sheldon Richardson (#9) and Dalvin Tomlinson (#94), both play a 3-technique on the outside shoulder of the guards. The two edge rushers, Danielle Hunter (#99) and Anthony Barr (#55) line-up as OLBs, or alternatively in a wide-9 position well outside the tackles on the line of scrimmage.

Michael Pierce, Dalvin Tomlinson, and even Sheldon Richardson are no strangers to double-teams. They’ve been doubled-teamed on many occasions- most snaps for Pierce and Tomlinson. So what happens when, in a Bear Front, they get a one-on-one matchup? Could be fun to watch.

In this illustration, all the run gaps are covered by the front five, and on a passing play it’s a five-man rush, putting stress on each offensive lineman to win their one-on-one battle against some pretty tough defensive linemen/edge rushers.

However, there is some nuance to it. In the above illustration, Anthony Barr rushes, in which case Harrison Smith (#22) would move up to cover the tight-end. But Barr could also press the TE initially, which may cause the tackle to double Tomlinson, and then rush the quarterback. The same is possible on the other side as well, with MacKensie Alexander (#24) blitzing, and Xavier Woods (#23) moving up to cover the slot receiver. Of course there are other options off the same formation, but against a suspect offensive line, and/or a quarterback that doesn’t do well under pressure, and/or a team without much for quality, go-to receivers, this front can create a lot of problems on passing downs, while still being effective against the run.

Running a Bear Front on a passing down traditionally means a Cover 1 scheme behind the front, with defensive backs in man coverage and a single high safety deep. This is basically a ‘we got the horses’ defensive call, both up front and in coverage, to both cover receivers and get to the QB quickly. But there may be a more effective coverage option.

Why use a Bear Front?

Apart from last season, the Vikings defense ranked pretty well overall without using a Bear Front, so why install it?

The main reason to install it is because it suits the Vikings new personnel up-front- the big, run-stuffing defensive tackles. It can also put more pressure, including interior pressure, on the quarterback on passing downs. And creating more one-on-one matchups for those big defensive tackles, not to mention the edge rushers, could give a big boost to the Vikings pass rush.

Cover-7

Last season, according to PFF, the Vikings played a wide variety of coverages, which along with the various adjustments to each one, makes for a complicated coverage scheme.

Vikings Coverage Shell and Percent of Defensive Snaps, 2020 Season, per PFF

Cover-0: 2.9%

Cover-1: 16.1%

Cover-2: 15.1%

Cover-2 Man: 2.1%

Cover-3: 16.1%

Cover-3 Seam: 4.9%

Cover-4: 14.7%

Cover-6: 8.5%

Other: 5.4% (goal line, red zone, prevent, bracket, etc.)

One possibility that could allow the Vikings to consolidate and simplify their coverage scheme is to install a Cover-7 scheme. The scheme has been around for at least a decade, but outside of New England hasn’t seen a lot of use. It’s more prevalent in the college ranks, particularly at Alabama, which has used it for years. New Vikings defensive backs coach Karl Scott spent the past three years coaching defensive backs at Alabama, so he’s well versed in the scheme. Additionally, new Vikings Senior Defensive Assistant Paul Guenther used a similar scheme as defensive coordinator with the Raiders.

So what is Cover-7?

Cover-7 is a pattern-matching coverage scheme which can be either a man-match scheme or a zone-match scheme. In a man-match scheme, a defender has a receiver in man coverage unless/until he does something that causes the defender to pass him off to another defender and cover another receiver in man coverage. That sounds pretty nebulous in the absence of the overall scheme structure, so let’s begin with that.

Above is an illustration of how the Vikings may line up initially in a Cover-7 man-match scheme, with the linebackers still covering their run gaps. It looks like a Cover-2 shell, with two deep safeties, but it’s not. Here is how Vikings’ Defensive Backs coach Karl Scott described it when he was giving a clinic on the concept while at Alabama:

“We call [Cover-7] ‘man-match quarters.’ It’s a split-field coverage. On the strong side, we’re going to play four [defenders] over three [receivers] and on the weak side, we’re playing three [defenders] over two [receivers]. How we’re playing [to each side] changes through calls that we make… We always feel like we have the advantage because we have one more than they have.”

So, as a split-field coverage, typically each safety makes the particular coverage call for his side of the field pre-snap. What that call is will depend on how many receivers are on his side, down and distance, personnel, etc. For example, the call for the outside cornerback may be ‘MOD’, which means he has the outermost receiver on his side in Man coverage for any pattern Outside or Deep. Typically the CB will position himself with inside leverage, lining up just inside the receiver, making it more difficult for him to run a quick slant route, for example. Any type of go or post or out or corner route, or even a deep in-route, the CB will cover him in man coverage. If the receiver runs a shallow crossing route, he’ll pass him off to an interior defender and work back to his deep quarter zone, potentially picking up a TE or slot receiver on a deep route, or another assignment dictated by the call. The decision to stay or pass the receiver is usually made early on- after 3 steps or so back into coverage.

Another possible call for the CB is ‘MEG,’ meaning Man coverage Everywhere he Goes, or straight man coverage. That allows the other two defenders to potentially go with a ‘bracket’ coverage, or double team the other receiver. Typically the forward defender (LB or SCB) plays a trailing man coverage, while the safety comes down over the top, creating a very tight window for the QB to hit, and a difficult reception to make with two defenders to break it up.

Lastly, the call could be MOD for the outside CB, and First to the Flat or ‘F2F’ for the LB/SCB on the 2nd from outside receiver, with the safety reading the quarterback, rallying to the ball and helping out where needed. In this case the LB or SCB will cover the first receiver to run either a shallow crosser or out/flat route. If more than one receiver does so, the safety will pick up the 2nd receiver.

Of course there are some other calls for more unusual formations/situations, but the gist of it is that defenders begin with man coverage responsibilities and either stay with their man or pass him off to another defender depending on the route he runs.

Using the same illustration as above, this is how the coverage might actually play out, given an MOD call for the outside CBs and these routes:

Why Cover-7?

With all the other coverages available, why the need for Cover-7? The idea behind Cover-7 is to blend the strengths, and minimize the deficiencies, of zone and man coverages. For example, most zone coverages can leave too much space for shorter routes to be completed, and have ‘holes’ in particular areas of the field that can be exploited, like seam routes in Cover-3 and intermediate out routes in Cover-2. On the other hand, traditional man coverage like in Cover-1 can lead to matchup problems against top receivers if you don’t have top CBs to cover them.

What Cover-7 does is to provide tighter coverage on short routes and deep verticals with man coverage, while establishing some pattern matching rules to help against more difficult routes and route combinations in man coverage. Additionally, Cover-7 uses leverage to help narrow passing lanes and create tighter passing windows. That makes it a bit easier for defenders than Cover 1, which is straight man coverage with a single-high safety, and is the preferred coverage any coach would love to use all the time - if you have shut-down talent at every defensive back position.

The other thing about Cover-7 that works is the split safety aspect in defeating seam routes. As Cover-3 proliferated across the league after the success Seattle had using it in the last decade with the Legion of Boom, offenses adapted and began focusing on Cover-3 beaters, which typically are seam routes that go between the deep zones. By 2018, the Expected Points Added (EPA) on seam route attempts 10-25 yards downfield was 0.46, compared to 0.05 for pass attempts overall. EPA attempts to measure the impact of a particular play on the score of the game. Against split safety coverages, they were still about as productive, but there were a lot fewer attempts as the receivers weren’t open as often.

The other thing to notice from the above graph is that deeper routes outside the numbers have pretty low completion percentages.

Patrick Peterson, who’s had a couple down years most attribute to his getting on the wrong side of 30, but it may have been more to do with the load he was asked to carry in Arizona, along with how he was used. First off, he had 691 coverage snaps last season- most of any cornerback in the league. That’s a pretty heavy load for any cornerback, let alone an older one. The other thing is that he was also asked to play in the slot at times, which didn’t help his stats. Overall, Peterson allowed a 100.8 passer rating when targeted last season, which was 52nd in the league according to PFF. But take away his more limited snaps in the slot, which include all 4 of his touchdowns allowed, and his passer rating allowed drops to 74.7 - one of the best in the league. In fact it was 10th best in the league among CBs with at least half his number of snaps. Even with his snaps in the slot, Peterson was the 5th least targeted CB per coverage snap overall, with 8.6 coverage snaps per target. Without his slot snaps, he’d have been the 2nd least targeted, at 9.3 snaps per target.

Bashaud Breeland, who’ll compete with Cameron Dantzler for the other outside CB spot, allowed a 67.2 passer rating last season per SiS (PFF has it at 90.0 - not sure why the difference). But SiS also has Breeland allowing just a 5.4 passer rating on passes 20+ yards in the air last season- best in the league apparently. According to this piece, Breeland was perhaps the best boundary cornerback on deep passes last season, but struggled more against shorter routes. In a Cover-7 scheme, where he’d likely be charged with covering more of the deep outside routes, he could do very well.

And then there is Cameron Dantzler, who after going through some rookie growing pains early last season and missing some games, finished the season from week 11 on with the 4th lowest passer rating allowed in the league - 41.9 - according to PFF.

Overall, that looks like a good 3-man rotation at outside cornerback for the Vikings, should they go with predominantly a Cover-7 scheme.

4-2-5 Defense

A few months ago I did a piece on the possibility of the Vikings going with a base 4-2-5 defense, and that remains a possibility, particularly if they adopt more Cover-7 coverages as well. As it is, the Vikings used a nickel defense with 5 defensive backs and 2 linebackers most of the time, particularly when facing 3 or more wide receivers. But looking at recent data, using a 4-2-5 or nickel defense against 2 TE sets makes sense as well.

In 2018, defenses matched 12 (1 RB, 2 TE, 2 WR) personnel with base defense (four defensive backs) 61% of the time, and offenses produced a DVOA of 3.1%, according to Football Outsiders. DVOA is meant to be a measure of efficiency relative to average in similar situations. When the defenses treated one of those tight ends like a receiver and matched with a nickel (4-2-5) defense, offensive DVOA dropped to -5.3%. That’s fairly conclusive, and intuitive as well, when you think about all the athletic, pass catching TEs entering the league in recent years. EPA results paint a similar picture, with EPA in 2 TE sets averaging 0.19 against base defenses, but only 0.05 against nickel defenses. EPA attempts to assign the impact of a particular play on the score of a game.

The explanation for those measures is pretty simple: too often defenses treat an extra TE as a blocker, rather than a receiver, and therefore employ a base defense, which isn’t as effective in pass coverage. If you consider that offenses had a negative EPA when running the ball out of 2 TE sets as well, that suggests even less of a need for a base defense. Given that nickel defenses are already used against 3+ WR sets (65% of offensive plays last year), and that it makes more sense to use them against 2 TE sets as well (25% of offensive plays), that leaves only 2 RB sets as a possible fit for a base defense. Last year teams used 2 RB sets on only 7% of offensive plays, and only a handful of teams used them more than 5% of the time.

Combining a Bear Front with Cover-7

One other possibility that would fit with Vikings personnel and may work well in multiple situations is a combination Bear Front and Cover-7 scheme. Given that a Bear Front uses 5 men upfront, and Cover-7 has seven guys in back, that’s one over the limit. However, creating an rush/cover option for Anthony Barr coming off the edge makes it possible.

Above, the Vikings are lined up in a Bear Front, with 7 men in the box, which makes a run play (7 on 6) unfavorable for the offense. On a pass play, Barr rushes the passer and checks the RB. If he stays in to block, as is often the case against a Bear Front, he continues his rush. If the RB goes out on a flat/wheel route to his side, he picks him up in coverage.

In coverage on the right side, Patrick Peterson is in man coverage with inside leverage, while MacKensie Alexander and Xavier Woods bracket the slot receiver.

On the left side, Cameron Dantzler (or Bashaud Breeland) man the outside receiver outside and deep, while Harrison Smith does the same with the tight end. If the tight end breaks inside for a shallow crossing route, Smith passes him to Kendricks, who is charged with first to the flat coverage, which could be either a crossing route inside or, if both receivers on the left side run deep/outside routes, covering the running back to the flat if he runs a flat/wheel route to the left side. If both the tight end and wide receiver run shallow inside routes, Kendricks picks up the tight end and Smith the WR. Dantzler having inside leverage makes running an inside route more difficult however, and most likely slower developing. If only the outside wide receiver runs an inside shallow route, Dantzler passes him off to Kendricks, and then covers the running back if he runs a flat/wheel route to his side.

As a result, the scheme provides good coverage against seam routes, four verticals, and also high-low/mesh routes, where two or more receivers run opposite crossing routes over the middle. Additionally, if the right wide receiver and slot receiver run a smash route (outside WR runs a hitch or inside curl route, while slot receiver runs a corner route), that is pretty well covered too.

With a Bear Front, the more typical coverage is Cover-1, which puts more pressure on defensive backs, particularly on crossing routes, which are difficult to cover in man coverage. Using this variation of Cover-7 makes it a bit easier for defensive backs in coverage, while also providing for a pretty strong pass rush that can force the issue early.

Bottom Line

Mike Zimmer is making changes to his defensive scheme this year, and has also invested in personnel that can make a lot of schemes work well. He started by investing in big defensive tackles that can plug running lanes, and continued by bringing in a couple veteran outside cornerbacks, to go along with some promising young ones, that can be called upon to defend the outside and deep routes especially, which is what they’ll be called on to do more often than not in a Cover-7 scheme.

Zimmer himself, an old DB coach, got involved early on that score in OTAs, working on what appeared to be inside leverage technique with Patrick Peterson (and later Bashaud Breeland - Cam Dantzler wasn’t practicing that day).

Zimmer isn’t often regarded as the innovator he has been as a defensive coordinator, perhaps due to his old-school demeanor, but he has done a lot to evolve his scheme over the years, keeping it fresh and offenses guessing, and following the 2019 season was looking to make more substantial changes in that regard. But Covid got in the way of that last year, as did the injury losses and turnover, so he put it off until this off-season, where all signs point to some significant scheme changes, not to mention personnel changes as well.

We don’t know for sure what the changes will be, but given the comments from coaches and personnel, those shown above would fit, allowing for fewer adjustments, players to think less, react more, and play faster. Given the background of the new defensive coaches, a move to install Cover-7 wouldn’t be surprising.

Having the big guys up-front in Michael Pierce, Dalvin Tomlinson, and Sheldon Richardson - will also allow for some 3-4 fronts, something all of those defensive tackles have done in the past. Being able to install more ‘set-piece’ defensive fronts and coverages during the off/pre-season, should help cut down on the adjustments needed week-to-week, and allow the Vikings’ defensive coaching staff to see which of the scheme changes will work best for their personnel.

It will be up to the coaching staff and players to get it all installed and reasonably well practiced in time for the regular season, but if things go well with the installation, the Vikings could have one of the best defensive units in the league this season.