Plugging the Holes: AFC East

Devin McCourty was one of the few consistent standout players on New England's defense. Jim Rogash/Getty Images

On Wednesday, Football Outsiders begins its Plugging the Holes series, in which it will target the offseason issues facing each team in the NFL by division. Sean McCormick begins with the AFC East.

In this edition, Outsiders tackles the Bills' run defense, the Dolphins' QB situation, the Patriots' defensive turnaround and the Jets' poor third-down defense.

Buffalo Bills: How can they fix the run defense?

Asking first-time defensive coordinator George Edwards to install a 3-4 defense despite inheriting a roster with a bunch of undersized front-seven players seemed like a bad decision way back in August, and nothing that happened during the season made it look any better. Edwards jettisoned the notion of a true 3-4 early on, subbing in Alex Carrington or Spencer Johnson on running downs, but it wasn't enough to prevent Buffalo from finishing dead last in our adjusted line yards stats. The Bills stuffed running backs at or behind the line of scrimmage only 13 percent of the time -- well below the league average -- and they were among the worst in the league at bringing down runners who reached the second level of the defense. During one particularly brutal three-game stretch, the Bills surrendered 689 yards on the ground, and they allowed at least 200 yards rushing in eight of their 16 games.

Nose tackle Kyle Williams was selected to the Pro Bowl on the strength of his 77 tackles and 5.5 sacks. Although that wasn't enough to make up for the porous linebacker play behind him, he established himself as the centerpiece around which the new defense will be constructed. Some big-name teammates are less likely to hang around.