Notre Dame's defense has been impressive in the first four games this season, to say the least.
The No. 10 Irish (4-0) have given up only 36 points in the first four games this year. That's the best the program has done since Notre Dame gave up only 20 to Boston College, Purdue, Northwestern and Michigan State in 1975.
Notre Dame's defense is ranked fourth in the nation in scoring defense, giving up 9 points per game. The Irish are No. 16 in total defense, giving up 291.3 yards per game, No. 23 in pass defense, giving up 178.8 passing yards per game, and No. 28 in rush defense, giving up 112.5 rushing yards per game.
The Irish are also tied for ninth in sacks, averaging 3.5, and they are plus-9 in turnovers.
Coach Brian Kelly said keeping teams from scoring and forcing turnovers are the two things that he is most happy about his defense.
Notre Dame gave up 20.2 points and forced less than a turnover per game in 2010, and last year, the Irish gave up 20.7 points and had a negative 1.2 turnover margin.
"I think it's always been predicated about the keeping the points down, and we've seen that there's been that increase each and every year," Kelly said. "We're keeping the points down, and we're also now taking the football away. I think we're close to as many turnovers as we had last year after week four.
"The combination of keeping the points down and not having, OK, you're a bend‑but‑don't‑break defense, now we're a stingy defense and we're a defense that can take the football away. That's the next level of championship defense."