According to
Phil Steele the toughest schedules in the B1G are:
- #2 Michigan
- #3 USC
- #6 Ohio State
Using the AP Poll and my weighting of HFA, here are their games against ranked teams ranked (by me) from what I think is the toughest to what I think is the easiest:

As
@ELA 's simulation indicates, I think that the Buckeyes have a schedule that could be really tricky. Even as #1 team, road trips to #5 and #6 are still, IMHO, probably toss-ups at best and a home game against #2 isn't much better than a toss-up. The road games against #14 and #22 are also far from gimmies.
If the Buckeyes are legitimately the best team in the Country then there is a chance they could go 12-0 on this schedule but the risk here is that if they are even just slightly less than that it wouldn't be shocking for them to go 8-4 on this schedule.
Michigan's schedule has, IMHO, less upside potential and less downside risk. The road games against #1 and #2 are literally the two toughest possible games but those are the only road games against ranked teams.