SI's Peter King wrote an interesting story for the NFL issue about hybrid/multiple front defenses, and how teams are confusing the hell out of opposing offenses with various fronts and attacks.It's very on-topic considering Michigan has an NFL defensive coordinator.
The stars of the article are Sean Payton and Rex Ryan, Mattison's predecessor in Baltimore.
Many teams have started doing what Rex Ryan did as coordinator for the Ravens and now does as Jets coach—flood one gap or blocker with two, three or even four defensive linemen or linebackers. That challenges a quarterback to change his protection call to keep more blockers in. On one play in that 2009 Jets-Saints game, New York showed a heavy rush on the left side; Brees kept a running back in to block ... and at the snap the Jets dropped a lineman and a linebacker from the group into coverage, negating Brees's protection call. "They rushed four but ate up six of our guys," Payton said. "They were able to double two of our receivers without leaving anyone open."
Lots of good things in this article.