News about our next head coach has been flying fast and furious over the last week, ever since it was announced that Leslie Frazier was fired one week ago today. There have been three defensive coordinators confirmed to have an interview lined up with the Vikings for their head coaching position: Todd Bowles, Dan Quinn and Ray Horton. And there is one thing all three of these candidates have in common: they either run a 3-4 defensive scheme or run a hybrid scheme that utilizes concepts of the 3-4 defense. Maybe I’m reading too much into it, but this suggests to me that there is a very strong likelihood that the Vikings could switch to a 3-4 defensive scheme next year.

So just what is a 3-4 defensive scheme, and do we have the personnel to run it? We in Vikings land have been used to a 4-3 alignment for so long, many of us may not clearly understand the differences. First off, the two numbers refer to the number of defensive lineman and linebackers that makeup the front 7 of the defense. In a 4-3 alignment there are four down lineman and three linebackers, and in a 3-4 alignment it is reversed with only three lineman and four linebackers. This swapping of a lineman for a linebacker makes the positional assignments and responsibilities of the scheme very different.

For a more in-depth discussion of the 3-4 scheme, I highly recommend checking out this article or watching this video. But to summarize the scheme, the biggest changes come in the responsibilities of the defensive ends and outside linebackers. One of the advantages of a 3-4 scheme is that it can confuse the opposing quarterback as he has to guess which outside linebacker is going to pass rush, and which one is going to drop back in coverage. This means that the outside linebackers have to be a bit bigger than they do in a 4-3 scheme, and must be speedy enough to get to the quarterback in pass rushing situations. They have to be able to handle coverage too, but their primary job will be to rush the passer. The other change is at the defensive end position. With only three down lineman, there is added responsibility for the defensive ends to be able to handle the running game. So, defensive ends in a 3-4 are generally bigger than those in a 4-3 and must be able to handle constant double-teams. Players who are regarded as "undersized nose tackles", but who also possess agility and speed are generally regarded as great 3-4 defensive ends.

One of the other big differences in scheme is how the secondary is treated. In a 4-3 alignment it is not uncommon to have five defensive backs and only two linebackers on the field in a "nickel" situation, or even six defensive backs and one linebacker in a "dime" setup. So, teams that utilize a 4-3 scheme must have 3 starting caliber cornerbacks and plenty of depth at that position. However, a 3-4 scheme will rarely put five defensive backs on the field and will utilize their base setup with 3 lineman and 4 linebackers almost exclusively, which usually means only four players in the secondary. The trade-off of course is that it does require having four starting caliber linebackers and plenty of linebacker depth.

So, do we have the players currently on the roster to be able to make a smooth transition to a 3-4 defense? Well, not exactly. But on the other hand, we don’t exactly have the players to continue the 4-3 scheme if we don’t resign Jared Allen and Kevin Williams either so we’re going to have to have a massive overhaul of the defense either way. If we were ever to make a switch to a 3-4 defense, this is the year to do it. Let’s go through the positional groups and take an in-depth look at how a transition might work.

3-4 Nose Tackle

On the Roster Candidates: None

We don’t really have a prototypical 3-4 nose tackle. The ideal size would be in the 325-360 range, and our heaviest tackle is Fred Evans at 305, and he’s a free agent this offseason. Louis Nix is probably the best prospect in the draft and likely a 1st round talent, but Daniel McCullers, Shamar Stephen or Mister Cobble (fantastic name btw) should also be available in the later rounds of the draft. We could also look to free agency where guys like Terrance Cody and Cam Thomas would all fit the bill. So, in order to make a switch to a 3-4, we would have to address what is probably the most important position of the entire scheme since there is no one on the roster capable of playing this position.

3-4 Defensive End

On the Roster Candidates: Sharrif Floyd, Letroy Guion and Chase Baker

We don’t really have a prototypical 3-4 defensive end on the roster either, although if Sharrif Floyd and Letroy Guion were to lose a little weight and gain a bit more speed, they might be able to fit the bill perfectly. Generally speaking 3-4 defensive ends should be between 285-300 pounds and be able to beat double-teams. This is a very similar responsibility as the 3-technique position that Floyd and Guion have experience with already. All of our defensive tackles are "under-sized" and would be great candidates to make the transition from a 4-3 tackle, to a 3-4 defensive end. We would likely have to address this via the draft and free agency though as only Sharrif Floyd shows any real promise.

3-4 Outside Linebacker

On the Roster Candidates: Everson Griffen, Brian Robison, Justin Trattou, Marvin Mitchell

The ideal 3-4 OLB will weigh between 255-270, and stand about 6’3"-6’5" and the four men above fall within those ranges. Even better, all four would make for a smooth transition to more of a pass rushing outside linebacker. Everson Griffen is perhaps the best candidate to transition to OLB, as he has gained a lot of valuable experience in his trial at linebacker last year and is just a phenomenal athlete. Brian Robison also began his college career as a linebacker before transitioning to defensive end, and his underrated athleticism would serve him perfectly as an OLB. Justin Trattou was generally regarded as more of a tweener DE/OLB coming out of the draft and was recently signed mid-year (further evidence that a switch is imminent?), while Marvin Mitchell is our heaviest linebacker. It’s worth pointing out that there are generally two types of outside linebackers. There is the "joker" position, which is the primary pass rusher and there is the other position, which needs to be equally good at coverage, run defense and blitzing. Brian Robison would make for a great joker with Everson Griffen or Marvin Mitchell serving as the jack-of-all-trades option opposite Robison that drops into coverage most often. While we have some great in-house candidates for this position already, we would likely need to address depth at this position too.

3-4 Inside Linebacker

On the Roster Candidates: Audie Cole, Michael Mauti and Gerald Hodges

The responsibilities of the two inside linebackers in a 3-4 scheme are very similar to the responsibilities of the middle linebacker in a 4-3 scheme. The main difference is that since there are two of them, one is considered the "Mike" linebacker and must be extremely athletic: able to drop in coverage, blitz, cover receivers and spy the quarterback. While the "Ted" linebacker is usually a bit bigger and stronger, and should be able to take on multiple blockers in the run game to allow the Mike ‘backer to roam and flow to the ballcarrier. We have two potential starters in Cole and Mauti, and it’s probably a longshot for Chad Greenway to transition to inside linebacker. With the lack of explosion Greenway showed all year, and a very high cap number relative to his performance this past season, Greenway would probably be a casualty of a change in scheme. Larry Dean is not considered here because he is too under-sized for a 3-4 scheme. Gerald Hodges is also a little undersized for this scheme, but could serve as a backup. We would need to address this position in the off-season as well.

3-4 Cornerback

On the Roster Candidates: Xavier Rhodes, Josh Robinson, Marcus Sherels, Shaun Prater

One of the benefits of making this scheme shift for the Vikings is that it would require less cornerbacks. We could rely almost exclusively on Rhodes and Robinson on the outside with Sherels and Prater backing them up. It’s true that we should still explore a free agent upgrade over Josh Robinson, but I think he would do a lot better lined up on the outside. Sherels and Prater proved to be league average options, which is about all you can ask for out of backup options. Cornerbacks in a 3-4 scheme must be able to handle both zone and man-to-man responsibilities with equal adeptness, and both Rhodes and Robinson can do both. Realistically, cornerback is a position we might not have to address in this offseason with a switch to a 3-4, but if Josh Robinson fails to take a step forward in development, it’s a position to address going forward.

3-4 Safety

On the Roster Candidates: Harrison Smith, Jamarca Sanford, Andrew Sendejo and Robert Blanton

Like cornerback, we seem pretty well set at safety with Smith, Sanford and Sendejo, although they all underperformed this past season. The responsibilities of the safety position are nearly identical as that in a 4-3 scheme with both free and strong responsibilities. We likely wouldn’t need to address the safety position this offseason, and if they continue to underperform it would be a position to target for an upgrade down the line.

The transition from a 4-3 scheme to a 3-4 scheme would hinge on three main things:

Securing a Nose Tackle, which we don’t currently have on the roster Transitioning Everson Griffen and Brian Robison from defensive end to outside linebacker Transitioning Shariff Floyd and Letroy Guion from defensive tackle to defensive end

These are all not necessarily the easiest things to do, but they aren’t out of the question either. The first one on the list is the most important and without securing a nose tackle, the entire endeavor would suffer a horrible, icky death. If the front office can’t find a nose tackle then it simply doesn’t make sense to switch to a 3-4 defense. But the other items on the list would require a lot of buy-in from the players and would also require some growing pains as players adjust to new positions. It took the Green Bay Packers several years to adjust to their new 3-4 scheme and players like Aaron Campman never quite made the transition work. That’s not to say the Vikings can’t make it work, but it does mean there would be a lot of moving pieces with a lot of potential for failure.

Should the Vikings switch to a 3-4 scheme? Well, it’s not a bad idea actually. Generally speaking players that fit in a 3-4 scheme are easier to find in the draft than players that fit a 4-3. There are far more options available for 3-4 defensive ends than for 4-3 defensive ends for example, and there will always be "big fatties" available at the nose tackle spot. At the end of the day, with the likely departures of 4-3 mainstays like Jared Allen, Kevin Williams, Erin Henderson and Chad Greenway now is as good a time as any to make a switch to a 3-4 defense.