How good has Jim Harbaugh made Michigan?

Jim Harbaugh won the offseason with satellite camps, shirtless "Peruball" and celebrity Twitter shoutouts. But there were doubts about how much winning Harbaugh would do when his first Michigan team took the field.

The answer so far: plenty. After opening with a 24-17 loss at Utah -- a setback that looks better by the week -- Michigan has dominated its past four opponents, outscoring them 119-7 in the past 15 quarters. The Wolverines have recorded consecutive shutouts for the first time in 15 years, and their defense has held opponents scoreless in 14 of the past 16 quarters. Their offense isn't a juggernaut, but Harbaugh has implemented a formidable power run game led by De'Veon Smith and an improved line.

The expectations for Year 1 of the Harbaugh era are being rapidly revised. Can Michigan challenge rivals Ohio State and Michigan State in the Big Ten East Division? How much should we buy into the past four weeks, as Michigan has defeated only one opponent (BYU) with a winning record? What's Michigan's ceiling this year, and what could stop the Wolverines from reaching it?

We asked coaches who have faced Michigan -- or soon will in the Big Ten -- to assess Harbaugh and the Wolverines as they prepare for their Big Ten home opener against No. 13 Northwestern. Coaches were granted anonymity in order to speak freely.