At one point you could trace every offense in the NFL to either Bill Walsh, Don Coryell, or Ron Earhardt/Ray Perkins. Meanwhile, almost every defensive coordinator in the NFL worked with someone from the Dick LaBeau tree or the Tony Dungy tree or the Bill Parcells tree. When NFL coaches innovate successful systems and concepts, other teams try to copy them immediately and eventually, the best branches from the original tree make their way across the NFL. 

Evaluating what systems the teams in the NFC North will be using this year is a good way to foresee how the team will perform. Let's go over them. 

Minnesota Vikings

Offense

The Vikings have gone all in on the McVay offense, minus the wide zone setups. Head Coach Kevin O'Connell was offensive coordinator for the Rams in the year that they revamped their offense for Matt Stafford, turning to a ton of empty and a lot of Cooper Kupp targeting, and that is the offense that O'Connell brought to Minnesota. It is similar to early Rams McVay and what Matt LaFleur runs, but it's certainly more aggressive and pass-centric.

The Vikings doubled down on that system this off-season, releasing running back Dalvin Cook and using their first-round pick on a running back who at least drives fast. It's a bold strategy when your QB is Krik Cousins, but it worked well enough for him to have a top 10 PFF grade and star on a Netflix show. Of course, a top-10 Kirk Cousins didn't even spell a top-20 weighted offensive DVOA, so maybe we should expect some level of regression for the team in the win/loss column. 

Defense

The Vikings are going from probably the most passive zone coverage defense in the league last season to one of the most aggressive man coverage defensive coordinators in the league. Brian Flores majored in Cover-0 in Miami and comes from the Bill Belichick Cover-1 tree. Minnesota doesn't really have the manpower in the secondary to play cover-0 or really even cover-1 more than 15-20 snaps a game, so it's possible Flores will evolve, but right now it looks like the team will be blitz heavy this season. 

Chicago Bears

Offense

Luke Getsy's formative years were spent on Mike McCarthy, Joe Moorhead, and Matt LaFleur. Moorhead is a spread guru who is hailed as one of the main RPO innovators in college football. With the Bears, Getsy has leaned more into Moorhead offense than anything Mike McCarthy or Matt LaFleur did in Green Bay. Of course, that is probably more of a result of his personnel (Justin Fields and no one else) than his personal preferences. 

I would expect the team to continue to major in spread QB run concepts and RPOs this year, but also start to add more and more of the Shanahan scheme that Getsy learned from LaFleur. 

Defense

Matt Eberflus learned the Tampa-2 defense from (Joe Barry's father-in-law) Rod Marinelli in Dallas. While Eberflus runs a lot more Cover-3 than Marinelli did, the basic strategy is the same - rush four, stunt on the defensive line, and play deep zone coverage. Sound familiar? The Tampa-2 defense is very similar to the Fangio scheme that has spread across the league over the past few years. It's not as popular as Fangio's because Peyton Manning murdered it in the oughts. 

Eberflus ran a good defense in Indy, but, like the offense, the Bears just don't have the personnel to run it well. Eberflus will likely need to adapt the scheme this year to attempt to bring more pressure from the second level. 

Detroit Lions

Offense

Like Kevin O'Connell, Lions offensive coordinator Ben Johnson has stolen the McVay/Stafford passing scheme. Unlike Kevin O'Connell, Johnson has merged it with one of the most diverse run games in the league. The Lions took the league by storm last year thanks to their aggressive pass offense and creative run game. Johnson rode the success to several head coach interviews before deciding to come back to Detroit for one more year. 

The Lions' offense is somewhat of a mystery going into the year. Jared Goff centric offenses tend to regress after the league has a year of tape to study and the Lions replaced their running back stable with slow Jordan Howard and more-of-a-wide receiver Jamhyr Gibbs. If Johnson really does have the goods to be next Guru head coach, the Lions won't miss a beat in year 2 of him running the offense and will continue to evolve to use Gibbs and Howard (and exciting rookie tight end Sam LaPorta) in more and more creative ways. We'll see.

Defense

Like Brian Flores with the Vikings and Matt Eberflus with the Bears, Lions defensive coordinator Aaron Glenn was forced to run his head into the wall trying to run his scheme (an aggressive press-man scheme combined with a lot of quarters and creative blitzing) with inferior talent. Around halfway through last season, Glenn did what Vikings and Bears fans hope to see this year, and adapted. By the end of the season, the team had improved enough to go from last in defensive DVOA to 23rd in weighted defensive DVOA.

Glenn's changes after the Lions' bye certainly contributed to the team going from 1-6 to 9-8. The defense used far less press man and basically stopped blitzing in the second half of the season. It will be interesting to see which system Glenn goes with in 2023. The team spent the offseason building up its secondary, spent a first-round pick on an off-ball linebacker, and has a few guys on the defensive line ready to take the next step. Will he go back to the Gregg Williams scheme and bring pressure from everywhere with his corners on islands? Or will he stick to the more modern scheme, putting an umbrella over the deep part of the field with zone coverage and stick to four-man rushes?