Michigan is allowing 0.5 yards per play fewer than the 2nd best team in the nation, per The Solid Verbal on Twitter: https://twitter.com/SolidVerbal/status/1043910151609159680.
The 2nd best team in the nation is allowing 0.4 yards per play fewer than the 10th best team. The dropoff from everyone else to Michigan is striking. They are also 4th in S&P thus far. I've seen a lot of people saying here that this defense is not as good as 2016, or even 2017, but the numbers don't appear to back that up.
Just thought I'd throw this out there for people who think the defense isn't that good this year.