The Defense and its improvement. Why?

[pbmax]

Matthews now causes more confusion than ever before. The defense was better when they flipped him between right and left for a while; now he can show up anywhere.

With Matthews in the middle, he has an impact to some extent on almost every running play, he is that fast and that good. Even if he is not involved in the tackle, he takes up blockers. He attracts attention and takes it away from others.

Raji being back makes the DL rotation better.
Raji having found the fountain of youth, and playing like he did in 2010 makes it even better.

Jayrone Elliot has simple made plays, even big plays. The kinds of plays that influence outcomes. I don't know if he can continue to do it, but so far it has made a difference.

Nick Perry being healthy (apparently) has made an effect. He has made at least one play of note in every game, even with relatively limited snaps.

Pass defense from middle linebackers through the first 4 games is much, much better than it was last year.

DBs are playing well, with no drop off from last year. The rookies so far have not played like rookies.

Perhaps overlooked, but a factor nonetheless: The offense has been more methodical, with fewer long strikes. This keeps the defense off the field, keeps them rested and requires them to play less.

All true, but I would start with Peppers being a threat beyond any other pass rusher they previously employed opposite Matthews.

But your points are still relevant since even Peppers presence didn't lead to a lot of Clay sacks until he moved into the middle.

Neal was healthy last year (mostly) and this year he and Perry are healthy. Plus Elliot. Plus a healthy Jones.

[Patler]

All true, but I would start with Peppers being a threat beyond any other pass rusher they previously employed opposite Matthews.

But your points are still relevant since even Peppers presence didn't lead to a lot of Clay sacks until he moved into the middle.

Neal was healthy last year (mostly) and this year he and Perry are healthy. Plus Elliot. Plus a healthy Jones.

I thought about Peppers, but discounted him for purposes of this discussion, because he was here last year, doing what he does. Peppers doesn't explain the difference from last year to this, but differences in those around him do.