To listen to linebacker Dorian Mausi, Duke's defensive players don't mind the challenge of stopping an offense that has pushed deep into the Blue Devils' end of the field.

“When it gets super hard, we'll smile because that's what we enjoy,” Mausi said. “That's what we like, that's what we're known for, that's what we do. That's what we've been doing all year.”

The mentality has worked for the 17th-ranked Blue Devils, whose bend-don't-break approach has led to a fast start in Mike Elko's second season. It's also an example of how, in a time of offenses commanding the spotlight, defenses led by new coordinators have been key in early success for multiple Atlantic Coast Conference teams.

The league has a nation's-best six unbeaten teams with No. 5 Florida State, No. 15 North Carolina, No. 18 Miami, Louisville and Syracuse joining the Blue Devils. Of that group, Duke (8.8), Syracuse (10.8) and Miami (12.5) all rank in the top 12 of the Bowl Subdivision ranks for points allowed per game under coordinators hired for the 2023 season; Louisville (19.0) ranks in FBS' top third with a new coaching staff under former Cardinals quarterback Jeff Brohm.

ACC Network analyst Eric Mac Lain, a former Clemson offensive lineman, said getting those performances is tougher than ever in a game built around audience-pleasing offenses with video-game outputs.

“We literally make rules nowadays that make it harder to play defense,” Mac Lain said. "It is nearly impossible just with how touchy you can or cannot be as a defensive back, the moves that you can or cannot do as a defensive end. ... So I would say it's very hard.

“And then on top of that, just schematically how crazy things are now and the things people do and how they're throwing the ball, RPOs. I mean, imagine trying to do that, trying to stop the run there and then — oh nope, just kidding — it's a pass right over your head.”

Duke (4-0) offers the ACC's best example of getting it done anyway ahead of Saturday night's visit from No. 11 Notre Dame.

Under first-year coordinator Tyler Santucci, the Blue Devils locked up preseason ACC favorite Clemson on opening night to allow just one touchdown, block two field goals and secure two takeaways to end deep Tigers drives.

They haven't let up since, allowing a total of five touchdowns in four games.

In 42 drives excluding ones truncated by halftime or the game's end, Duke has forced a punt on 20 (47.6%), grabbed a takeaway on eight (19%) and held on downs six times (14.3%). Two of the five TDs allowed came in the final 90 seconds of blowouts against Northwestern and Connecticut.

Two years ago, Duke allowed 516.8 yards and 39.8 points in its final season under David Cutcliffe. The Blue Devils haven't held opponents to fewer than 20 points per game through a full season since 1975, and fewer than 300 yards since 1973.

They've done it with a physicality uncommon for Duke in recent years, while Mac Lain pointed to their speed that notably yielded little separation to Clemson receivers and rarely missed open-field tackles.

“If you look at who has won football games over the years, it's teams that play physical,” said Elko, himself a former defensive coordinator. "It's teams that punish, you. It's teams that play extremely hard, that's the recipe.

“You don't see a lot of teams winning national championships scoring 50 a game and giving up 40 a game,” he added. “Those teams create headlines and those teams are fun to watch, but that's not the teams right now that are winning championships.”

Syracuse (4-0) is thriving under veteran coach and 3-3-5 scheme guru Rocky Long entering Saturday's visit from Clemson. The Orange allowed seven points while overwhelming Colgate and Western Michigan to start the year, then had six takeaways and six sacks in wins against Purdue and Army — including holding the run-heavy Black Knights to minus-4 yards rushing after halftime.

“Our motto is everybody just play hard and fly around and we get the ball back to the offense,” linebacker Marlowe Wax said after the Army win, adding: “We're just trying to get the ball back to them, that's really all it is.”

Now it's a matter of how well those defenses can continue those fast starts. The league's six unbeaten teams have combined to play six league opponents, with Miami (4-0 entering an open weekend) and Syracuse yet to play an ACC game. So schedules, and challenges ahead, will get tougher.

That's why Elko isn't eager to discuss defensive accomplishments just yet.

“This is going to be the stretch that defines who and what we're about,” Elko said. “That's not just this game, that's really the next eight. We're off to a good start but we're a third of the way through. So let's have those conversations down the line sometime."