Offense in the NFL is almost completely rooted in the Bill Walsh West Coast or Don Corywell (also west coast) offense. Defense is a little more diverse, but not much. You have the guys who want to sit back in a soft zone and make the defense go to the length of the field, the blitz maniacs, and the man coverage guys. The are obviously different branches to each. For example, the soft zone guys can come from the Pete Carroll Cover-3, Tampa-2, or Vic Fangion quarters/Cover-6 trees and sometimes a coach,like Brian Flores, will jump off the Cover-1 tree onto the blitz maniac tree. Let's look at how each of the inferior NFC North teams wants to play defense and try to figure out how that will influence them this off-season. 

Bears

Let's start with the Bears. The team's defense changed completely when Matt Eberflus took up play-calling and they traded for Montez Sweat. Sweat gave them the combo of elite run stuffing and plus pass rush that they needed for the defense to come together. 

Eberflus is a dyed int he wool soft zone guy. He's part of the Rod Marinelli tree and though he has diversified into more cover-3 use than Tampa-2, the general philosophy is the same - force the defense to move the ball down the field slowly and get pressure with four. Pre-Sweat the defense didn't work because everyone got the ball down the field fast and the Bears never got any pressure. Post-Sweat (and Jaylon Johnson taking off, finally) the defense was good enough to get up to 17th in DVOA on the season. 

So what's next for the Bears? Priority number one should probably be re-signing Jaylon Johnson. They have the cap space to gamble that his play wasn't a contract-year-only improvement. The next step is continuing to beef up the d-line. Starters Justin Jones and Yannick Ngakoue were two of the worst at their position in the league last season and Andrew Billings has not been consistently good (or bad) in his career. They can't stop there, though. Their other starting corner is horrific and their safeties are average at best. 

Vikings

Brian Flores has an interesting history. He was linebackers coach and de facto defensive coordinator/playcaller in New England (where he received a head coach interview from the Packers), got the head coach job in Miami, was let go and went to Pittsburgh for a season, and is now back in a playcaller position. In New England he ran the Cover-1/multi-formation defense that Bill Belichick wanted. He kept much of that in Miami, but evolved into a cover-0 heavy aggressive defense that incorporated some college concepts. In Minnesota, he's gone all in on the college concepts, effectively running the NFL version of the Pat Narduzzi defense.

That means a lot of creative blitzing and tight man coverage, but also a lot of dropping into 8-man zones that almost no one in the NFL runs. It's a fun scheme and it did really well for the Vikings for a 10-game stretch or so, but it makes it hard to predict what types of players the team will try to bring in. 

Do they want defensive linemen who can win their pass rush battles consistently or do they trusts Flores' scheme to generate pressure? Do they want the type of hard-nosed blitzing inside linebackers and do-it-all chess piece safety that Bill Belichick has always preferred? Do they want corners who can excel in man or corners who can play zone well? We do know one thing: they need more guys. 

Danielle Hunter is a good edge but he's no longer in the top two or three tiers and none of their other d-linemen are anything to write home about. Harrison Smith has been an effective player for a long time but he was born in the 1980s (!). Can you even name one of their corners without looking them up? My guess is that instead of trying to find the perfect fit for Flores' scheme, the Vikings will take the best defensive players available and let Flores evolve his scheme to fit them in. Flores does enough different stuff that any player with true talent can work. And the Vikings need talent. 

Lions

The Lions are the hardest of these teams to pin down. Aaron Glenn comes from the Dennis Allen tree where they play a lot of aggressive press man, don't blitz, and utilize heavy d-linemen across the board to stop the run. Glenn has toyed with zone coverage and blitzing in Detroit, but one thing the team focuses on, before all others, is stopping the run. 

The Lions probably had one of the worst secondaries in football last year. They also had one of the worst secondaries in 2022. Last off-season, they brought in a few JAGs to the secondary and drafted an inside linebacker in the first round. Even the safety/corner who they used a second round pick on, Brian Branch, is a stronger in run defense than pass coverage. So what do they need to do to keep shoring up the run D? 

The first step, is bringing in a thicker edge to go across from Aidan Hutchinson. Hutchinson was just average at run defense last year, but hitting on another good edge while Alim McNeil stays the course could give them on of the better starting D-Lines in the league. 

Let's say they change lanes and decide to focus on the pass. What do they do then? The answer is probably spend all their off-season capital on the secondary. Branch is the only player on that level of the defense who consistently plays above replacement level.