EAST LANSING, Mich. -- It doesn’t take much to get Pat Narduzzi fired up. But if you really want to get him going, ask about this year’s Notre Dame game.

In September, the Irish took advantage of four pass-interference penalties and a defensive-holding call to hand Michigan State its only loss of the season. Asked during a recent visit from ESPN.com whether that game prompted any changes to his aggressive style, the Spartans’ defensive coordinator loaded film of the questionable calls onto his computer and grew more animated as the plays unfolded on the screen.

The defense run by Pat Narduzzi seems simple but the complexities are beneath the surface. AP Photo/Al Goldis

“We didn’t make any adjustments,” he said. “I think the officials had to make adjustments. Just because guys can’t get open doesn’t mean it’s on us.

“After that game, I continued to say to our guys, ‘Hey, that’s what we do, and that’s how we do it. We’re not going to change.’”

Why would Narduzzi change a thing? Michigan State leads the nation in total defense and rushing yards allowed and is No. 4 in the FBS in scoring defense, giving up just over 11 points per game. The Spartans are understandably confident in their way of doing things heading into Saturday's Big Ten title game against Ohio State.

“We’re going to play our game of football,” senior cornerback Darqueze Dennard said. “We’re going to make those guys play our game.”

Continuity is a core belief for Narduzzi, who is in his seventh year at Michigan State and ninth straight season running a defense under Mark Dantonio. There’s no real secret to Narduzzi's system, which seems simple in its appearance but is complex beneath the surface.

Michigan State lines up in the same 4-3 base on almost every down except for third-and-long, when it will move to a three-man front. Against spread teams and passing attacks, the Spartans (unlike most defenses) will leave their three linebackers on the field instead of adding more defensive backs. They demand that their cornerbacks defend receivers one-on-one, freeing up safeties to help against the run.

“People know how we’re going to line up, for the most part,” Narduzzi said. “They now where our DBs and our LBs are going to line up. But that’s an advantage to us, too. You may know where we are, but so do we.”

Sounds pretty basic. And it is -- except for the zone blitzes that Narduzzi dials up out of that base package. A fellow Big Ten defensive coordinator called Narduzzi earlier this season, looking for tips to stop a common opponent. Narduzzi said the coordinator told him, “Man, that pressure you bring, I don’t know how you do it.”

That’s one reason why few other teams have copied Michigan State’s defense, despite its dominating statistics in recent years. Another reason is that not every coach is comfortable playing his corners on an island and blitzing, opening the defense up to potential big plays.

“People know what we’re doing, but they don’t know how we do it,” Narduzzi said. “We’re the only team in the country that does zone pressure like this. There’s a risk to it if you don’t know what you’re doing.”

That’s not a problem for these Spartans.

Since defenders mostly stay at the same spot on the field during almost every situation, they can master their particular craft. This year’s defense has certified experts at their jobs who have been in the system for years, such as Dennard, linebackers Max Bullough and Denicos Allen, safety Isaiah Lewis, and defensive end Marcus Rush. As Ohio State offensive coordinator Tom Herman said Monday: “They’re like a fine wine. They get better with age.”

Cornerback Darqueze Dennard led Michigan State in passes defended (14), pass break-ups (10) and interceptions (4) this season. Matthew Holst/Getty Images

“That’s been really the main part of our success,” Dennard said. “Just knowing each other and playing with each other for such a long time.”

The veteran players have taken ownership of the defense. Led by Bullough, they're able to make their own adjustments during a game when something isn't working, which is one reason why Michigan State hasn't allowed a second-half point in seven of its 12 games. Dennard had "No Fly Zone" T-shirts made for all the team's defensive backs.

Narduzzi and Dantonio both agree that this is the best defense they've had in their seven years at Michigan State. And this Ohio State team may be their toughest challenge in that time.

The Buckeyes are averaging 48.2 points and 321 rushing yards per game. While Narduzzi says some opponents this year have abandoned the running game against his defense, that won’t happen Saturday versus RB Carlos Hyde and QB Braxton Miller. Narduzzi is so concerned about stopping them that he has gone to full tackling in practice this week, something the Spartans didn’t do before last season’s 17-16 loss to the Buckeyes.

“For me to sit here and tell you it’s not our biggest test, I’d just be lying to you,” Bullough said. “But it’s something that in all reality, we look forward to.”

Different year, different teams. But last year, Michigan State did hold Ohio State to its lowest point total in two years under Urban Meyer, while Narduzzi still laments a fumble return for a touchdown by his defense that was blown dead by the officials.

“Obviously, it’s a bigger challenge in who you’re playing,” he said. “But we played them a year ago, so it’s not like we don’t know who we’re playing against. It’s an opportunity for us to go clean up something from a year ago.”

Narduzzi hopes the result is different this time around. But little else will change for him or the Spartans' defense.