I think the thing New England has on its side that allows it to be so creative defensively is the versatility of its players.
Yeah, and Belichick. I read in Sports Illustrated that he was at LSU with Nick Saban right after the Super Bowl scheming up new defensive looks. He's come up with a hybrid between the Cover 2 defense and the Cover 4. The defense gives the look of a cover 2 and then transforms into the cover 4. He is just always trying to come up with new looks.