What we know, what we don't know about Michigan football after five games

Michigan Wolverines football is off to its fourth 5-0 start under ninth-year head coach Jim Harbaugh, with blowout victories over East Carolina, UNLV, Bowling Green, Rutgers and Nebraska. The Maize and Blue have had a weak schedule in the early going, though, so it can be tough to judge just how good the No. 2-ranked team is. Below, we take a look at some things we know and don't know about Michigan through five weeks.