Grantland has a piece on Friday by Chris Brown that traces the evolution of the Patriots' hybrid defense and the role veteran Vince Wilfork has played in stabilizing "a motley group of undrafted rookies, castaways, and converted wide receivers."
It reads, in part:
Aside from discussions of its general mediocrity (or worse), the hottest topic about the Patriots' defense has been how hard it is to define. Is it a 3-4 defense (the three-defensive linemen, four-linebacker defense that Belichick has run for two decades)? Or is it a "4-3" (the four-defensive linemen, three-linebacker set that New England has favored this year)? The truth is that they play a bit of both.
Then again, simple labels like 4-3 and 3-4 don't tell the full story. These 4-3 and 3-4 teams typically differ in a key respect: which "technique" their defensive linemen use. Usually, teams must commit to one technique or the other, as each choice has all sorts of other implications for the defense. It's truly a philosophical choice. Yet Belichick and his vagabond defenders have found a way to get the best of both worlds (relatively speaking) to best fit the Patriots' strengths. To understand Belichick's strategy, we have to understand how these techniques have evolved over time.