The best offense in college football. One of the worst defenses in the Big Ten. On paper, very little has changed for Southern California.

The Trojans are averaging a Bowl Subdivision-best 8.5 yards per play. They rank fifth nationally in yards per carry. The passing game is one of three in the Power Four with at least 150 attempts and fewer than two interceptions.

But the defense ranks 82nd in the country in yards allowed per play even after opening the year against Missouri State and Georgia Southern. USC is allowing 6.5 yards per play and 27.3 points per game in three Big Ten matchups.

What could be a make-or-break year for coach Lincoln Riley hits a tipping point against No. 15 Michigan, the sort of physical, in-the-box opponent that has been the Trojans’ kryptonite since joining the Big Ten last season.

A year ago, the Wolverines ran for 290 yards and won by a field goal. Two games later, Minnesota went for 193 yards on the ground in an upset. Notre Dame had 258 yards on 6.8 yards per carry in taking the season finale.