-Their defense was trash last year, then they fire their defensive coordinator a couple weeks before playing us.
-Meanwhile, Wake Forest had one of the worst offenses in the FBS, but one of the best defenses, led by DC Mike Elko. In 2016, Wake Forest's defense ranked in the top 20 for FBS in defensive touchdowns scored, turnovers, red zone defense, sacks, and scoring defense. Only 3 other teams did that last year, all playoff teams (Washington, Clemson, and Bama). He had a playoff caliber defense at wake forest....
-During the off season ND hired Mike Elko and his LB coach. So he pretty much brought a playoff caliber ACC defense to ND and ofcourse, they have much better talent than Wake Forest. This explains why ND defense is much better than last year, and also explains why ironically...Wake Forest put up the most points on them. They know his defense better than any other team.