Mike Trgovac was a nose tackle at Michigan in the late 1970s, and that was the last time he was with a team that used a 3-4 defense until he became the Packers' defensive line coach in 2009.
"I love this defense. I loved it when I played in it," Trgovac said of the 3-4, which Packers Defensive Coordinator Dom Capers has helped popularize over the last two decades. "It gives you a lot of flexibility. They never know who the rush guy is going to be."
Trgovac is especially fond of how the 3-4 lends itself to pass-defense, which is the reason so many teams have made the switch to the 3-4 in recent years. Today's NFL is a passing league and the 3-4 is built to not only rush the passer, but to defend against the pass.
Here's an example of the 3-4's adaptability:
In "nickel," the defensive ends come off the field and are replaced at the line of scrimmage by the outside linebackers in a four-down-linemen scheme.
"You have nine guys on the field that know what pass-coverage calls are, instead of seven. You can do much more out of the 3-4 because you're teaching them coverage all the time," Trgovac said, referring to the fact that linebackers are all involved in pass-coverage drills, whereas defensive linemen are not.
The linebackers are the stars of the 3-4 and defensive linemen must be willing to accept a lower-profile role. They must be willing to toil in anonymity.
"We're not asked to be stars. We're asked to do the grunt work. When you do your job right, those guys (linebackers) come free," Trgovac said.
The perfect example of that happening is the game-changing play in Super Bowl XLV in which linebacker Clay Matthews came free and forced Rashard Mendenhall to fumble following a jarring hit. Defensive end Ryan Pickett helped make the play happen by following Matthews' instructions to "spill it" to the outside.
"You look at Pittsburgh. Give me five guys who know who those three people are," Trgovac said of the Steelers' front three. "The first thing Pittsburgh does is make sure they have a good nose. Pittsburgh has Casey Hampton. New England has Vince Wilfork. We have B.J. Those guys make the Pro Bowl because the players know those guys are hard to block."
Packers nose tackle B.J. Raji became a star when he intercepted a pass in the NFC title game and returned it for a touchdown. Trgovac said Raji disguised his drop perfectly, delaying it just enough to not have his intentions detected.
That kind of star-power play, however, is the exception, not the rule for 3-4 defensive linemen. Mostly, they are asked to take on double-teams and two-gap and keep blockers off the backers. It's a thankless job that goes to the heart of a 3-4's success.
"There are plenty of opportunities for them within the defense," Trgovac said, but they have to be patient as they wait for those chances to arrive.
Trgovac is a former defensive lineman with the personality of a guy whose hand will forever be on the ground, yet, he coaches in a game that is being directed away from the line of scrimmage, even to the point of talk about eliminating three- and four-point stances. Should that happen, it would threaten to eliminate defensive linemen from the game.
"It would become even more of a passing game. They want to make it seven-on-seven. Hopefully, that'll never fly because I love the game the way it is now," Trgovac said. "The fans want to see who the best quarterback on the field is. I'm not for hurting quarterbacks, but you have to be careful about making it too soft."