I'm a little surprised the Green Bay Packers run defense has gotten off to such a good start. From the Journal-Sentinel:
Start with two massive nose tackles. Blend in two hard-nosed outside linebackers. Oversee with a coordinator who believes defense begins with stopping the run.
That's the main ingredients of the Green Bay Packers run defense, much improved and residing atop the National Football League rankings after three games.
It's basically the same guys that were below average last season. However, they were also outstanding in 2009.
The big change from 2009 to 2010 was the switch from Ryan Pickett to B.J. Raji at nose tackle, and this season they've switched them back with Raji playing the defensive end spot vacated by Cullen Jenkins. While that bit of line shuffle isn't necessarily the reason for the improvement, it does look like the change suits Pickett, who's become the type of player who seems to play better in odd numbered years. His health might also have something to do with it. Though Pickett has played better at nose tackle.
The quality of their opponents also has a lot to do with it. Back in 2010 according to Football Outsiders, the Saints, Bears, and Panthers were all bad rushing teams, with only the Bears approaching average, and there hasn't been a lot of improvement for those three teams this season either. The Broncos aren't very good at running the ball this season (28th overall according to Football Outsiders), so expect the dominant run defense to return again this Sunday.