Notre Dame hired coach Brian Kelly largely because of the high-scoring offenses he engineered at Cincinnati.
But the Fighting Irish are back in the national spotlight because of their defense.
Notre Dame is 4-0 for the first time in 10 years behind a defense that's ranked fourth in the nation at just nine points allowed per game. The revitalized Irish are helping prove that defense still matters most in football, as the top nine teams in scoring defense are all unbeaten.
NO-TOUCHDOWN JESUS: Notre Dame hasn't allowed a TD in two weeks, beating rivals Michigan State 20-3 and Michigan 13-6 on Saturday night. The Irish forced the Wolverines into six turnovers, including five by star quarterback Denard Robinson, and are now tied for second nationally with 13 takeaways. Mississippi State has forced 15 turnovers, which is a big reason why the Bulldogs are also off to a 4-0 start.
TOUGH FROGS: TCU was the last team in the country to allow a touchdown when Virginia's E.J. Scott caught a TD pass late in the fourth quarter of a 27-7 loss to the Horned Frogs on Saturday. But TCU is the only team in the nation to let up just one touchdown and is first nationally at just 4.3 points allowed per game. That number will likely go up once conference play starts, but the high-powered offenses of the Big 12 have surely taken notice of the defense their newest conference member is playing.
SEMINOLE SLIPUP: Florida State's reign as the nation's top defense ended courtesy of Tajh Boyd and the Clemson Tigers, who on Saturday night hung 37 points on a Seminoles team that had posted back-to-back shutouts. But coach Jimbo Fisher will take it, since Florida State prevailed 49-37 to take a decisive early lead in the ACC's Atlantic division. The Seminoles still rank sixth in the nation at 10 points allowed per game because they gave up just a field goal in the first three weeks of the season.
BLACK AND BLUE BRONCOS: Boise State has become known in recent years for racking up ridiculous offensive numbers on its famed blue turf.
The Broncos leaned on their defense to survive a stern test from BYU on Thursday night.
Boise State prevailed 7-6 on Michael Atkinson's 36-yard interception return early in the second half. It was the first time the Broncos were held scoreless in the first half under coach Chris Peterson, who took over in 2006. But Boise State's defense forced five BYU turnovers and stuffed the Cougars on a late two-point conversion try.
EXTRA POINTS: How good has top-ranked Alabama been this season? The Crimson Tide hasn't even let up a field goal yet. Just three touchdowns and 5.25 points a game, good for second-best in the country behind TCU. ... Rice has the nation's worst defense at 45.8 points per game after losing in overtime to Marshall 54-51 on Saturday. The Herd's scoring defense is 118th out of 120 teams - not including provisional FBS teams like Massachusetts - but they're a respectable 2-2. ... Surprising Stanford leads the nation in rush defense at 41.3 yards a game. Texas Tech, which is known for its passing offense, is 3-0 in part because it has the nation's best passing defense at just 85 yards a game.