My first reaction to the trade of Julian Peterson was "Are you fucking kidding me?" Upon further reflection, this trade is understandable, but I don't see it as an improvement one way or the other.
The Seahawks were changing to a base tampa two where the pressure was to be generated by the front four, Peterson is poor against the run and struggles mightily in coverage(Such a change from his younger years), he has poor gap control, poor play recognition and poor tackling. However, the whole defense couldn't tackle or stick to their gaps last year. He's still a capable pass rusher with the perfect build and uses his hands extremely well. He was also horribly used. I don't understand the stunts to the inside that had him pushing in the middle and a DT containing the outside. Doesn't make sense in so many fundamental ways I can't even list them here, but I'll address it later, because that exact philosophy is why this trade was made in the first place.
Cory Redding is going to be used at defensive end the first two downs and moved inside on passing downs(As Kearney was occasionally last year).
I think this is inanely stupid but Redding is a better fit for it than Kearney, he is better built for rushing on the inside and has more experience. However, I don't get the idea of having smaller guys rushing in the inside lanes on 3rd down.
Defensive ends use a variety of different things to get to the quarterback. They use speed to get the offensive lineman off balance, if they use their speed to get to the edge and he turns his hips, they can rip to the inside. If they don't pop out quick enough, they can swim around the end around the end, or they can use their speed to generate explosiveness and power through the lineman with the bull rush. Part of the reason defensive ends can get pressure on the quarterback is that they can work in space, aside from a back helping out or a tight end chipping, its one on one. Inside rushers have to rely on technique and strength. There isn't as much space to work and the center or guard is there to help out. Guards and centers are typically shorter than tackles and have shorter arms so that they can get to the defenders chest, they don't need great reach because of the lack of space they are protecting. If you get pressure up the middle from your defensive tackles, its typically a bull rush and they are collapsing the pocket. That way the tackle is getting pressure and still maintaining his gap integrity. If the tackle tries to skirt around the outside, unless the guard or center has a failure of technique and is caught leaning forward, the offensive linemen can push the rusher up and to the side, clearing out the middle of the field for the quarterback to step up. Ideally you want a push up the middle causing the quarterback to glide backwards in the pocket into the ends coming around the edge. Even if a pass is thrown, the quarterback is unable to fully step into the throw and in most cases these days, the quarterback is throwing off his back foot. Placing ends on the inside means that you won't have that push, instead you have them trying to get upfield, leaving their gaps open and allowing the quarterback to step up in the pocket with now a multitude of new options, A) The quarterback can run, if in man coverage this is the best bet, if in zone, he can still gain 3 or 4 yards at minimum or B) the quarterback now has a clear view of the field and doesn't have to rely on passing lanes, his throwing angles are different but when the quarterback moves, coverage typically breaks down and holes will open up behind the linebackers, who move up thinking the quarterback might run.
In philosophy, putting all your ends out there to rush the passer seems like a logical idea. But it simply doesn't work. They either get stonewalled or run themselves out of the play. It sounds like something you'd try in a video game.
I think this strategy will work with marginal success at best, the Seahawks are doing what they've been doing the last couple years on defense, they are failing to maximize the talent of their players and use them where they have the highest chances of success.
I think the Seahawks defense will be more disciplined against the run next year, Peterson was a liability in that regard and their are putting a defensive line together that will keep the linemen and fullbacks off the backers, but on third down, the ultimate thorn in the side of the Seahawks last year, I doubt we will see a significant improvement. Due to changes in the secondary scheme, it will be improved, but the scheme is still flawed and the talent lacking.