When Carroll came into the NFL, he came with a unique prospective. Many of the guys we brought onto the team, Pete had experience with in some way, either coaching, recruiting or coaching against. Carroll also had an insight that most in the NFL missed. You see, previous to Pete, big corners were often seen as a liability. The prevailing thought was their hips would be too tight and coverage and they wouldn't be able to make the transitions quick enough. Carroll saw many of the offenses trending towards bigger receivers. He was able to properly identify an overlooked class of players.
Carroll's defenses back then still used the same coverage schema, but the defense was far more aggressive. We would line up right across from the receivers and mug them at the LOS with heavy press coverage. It was virtually impossible for some of those opposing receivers to get off of the likes of Brandon Browner and Sherman. To mitigate his corners weaknesses, we leaned heavily on a rangy free safety. You see, Thomas made all of this work. Thomas was fast and he could cover a lot of ground. Chancellor acted almost like a fourth linebacker at times and was given credit for being the field general and leader of the defense.
Carroll's playbook was dead simple and the players noticed it too. The main thing here was it required a lot of discipline, communication and everyone doing their job.
Pretty soon everyone was clambering for undersized pass rushers and giant corners. This means, the players the Hawks got insane value out of were now in vogue. Another issue that cropped up was building this style of defense was EXTREMELY expensive. Dan Quinn mentioned as much in an interview while he was with the Cowboys. He said it was still an effective system, but it's hard to assemble all of the right players for the job. It's an honest system that is just lining up and allowing players to do their thing. The assignments were easy and dead simple, but it worked on the principal that everyone has to execute those simple concepts.
Seattle went on to have the most seasons straight of being a number 1 defense in scoring. I believe it was something like 5 years of dominance. The problem is, the NFL is called the not for long league for a reason. Teams adapted as this became the main defensive meta. The NFL also made several changes here that specifically cracked down on this defense. They made it harder to press corners like we did. Several rule changes really neutered this defensive philosophy.
The changes to the NFL rules are what really started Pete's downfall imo. First thing that happened is several changes, including less practice time, and less physical practices. If you remember, Pete and the Seahawks got fined for being too physical in practice. Sounds like something that is hard to believe after watching the current iteration of the Hawks doesn't it? Offenses also came out that were REALLY good at exploiting this style of defense. Shanahan and McVay practically wrote the book on exploiting this defensive scheme.
This is where things really start to go downhill. After Dan Quinn, Pete really dropped the ball on the hires. Ken Norton Jr. and Clint Hurtt were unqualified for the job, while Richards just wasn't a great DC. It became clear to Carroll that the changing landscape of the NFL was leaving his scheme behind and he had issues finding the personnel to play his defensive correctly. The issue here is, we tried implementing systems that neither he, nor the staff he assembled knew how to run properly.
With the Seahawks defense had to adapt with the changing landscape of NFL offenses, but Pete didn't hire the right guys to tackle that job. I also ponder if the changes in practice rules in addition to trying to implement a scheme that Carroll had little experience with had anything to do with the Seahawks poor discipline and tackling.
We also have to talk about Pete Carroll's tendency to not hold his coaches accountable or his QB accountable. Bevell stood up there on the podium after the Super Bowl call and blamed his players. Russell, and Pete took responsibility, but Bevell refused to do so. We hung onto Cable and Bevell for way longer than we should've. We brought in Schottenheimer who was actually very successful here in Seattle and showed him the door because we were trying to placate a passive aggressive QB that was having a temper tantrum, despite being put in the best position to succeed given his skillsets.
Pete's I'm in, we all we got, we all we need philosophy he crafted backfired when there was a lack of consistency, especially with his coaches. I've heard KJ say that he often avoided having the hard conversations. Lack of accountability was a huge problem at the end of Carroll's tenure here in Seattle. It's also worth noting that during the LOB's prime, they often held themselves accountable. Kam Chancellor and Doug Baldwin would call people out if they weren't doing their jobs.
Pete's management style was both a gift and a curse at the same time. Players just started checking out after awhile and having a caviler attitude. We also started bringing in a bunch of guys that didn't fit the scheme or culture here in Seattle (Jamal Adams, Harvin, Graham).
TL;DR
Pete Carroll's scheme was neutered with rule changes, didn't hold the right guys accountable, struggled to adapt to modern NFL offenses and rule changes, hired the wrong guys to implement changes on defense.
