The Michigan offense cannot really be any better than it was in 2010, but the defense almost certainly cannot be any worse. What is the defense's upside following such a crater of a season? Here are the ten largest single-season improvements (according to Def. F/+) and where such an improvement would have placed Michigan in last year's Def. F/+ rankings:
Largest Single-Season Def. F/+ Improvements
1. 2009 Nebraska | Improvement: +26.3% | Where Michigan Would Rank: sixth
2. 2010 N.C. State | Improvement: +21.4% | Where Michigan Would Rank: 22nd
3. 2008 Florida | Improvement: +20.6% | Where Michigan Would Rank: 23rd
4. 2007 Louisiana Tech | Improvement: +17.8% | Where Michigan Would Rank: 36th
5. 2010 Illinois | Improvement: +17.4% | Where Michigan Would Rank: 37th
6. 2007 Temple | Improvement: +16.8% | Where Michigan Would Rank: 38th
7. 2009 Middle Tennessee | Improvement: +16.4% | Where Michigan Would Rank: 38th
8. 2010 Notre Dame | Improvement: +16.3% | Where Michigan Would Rank: 39th
9. 2010 Florida Atlantic | Improvement: +15.9% | Where Michigan Would Rank: 43rd
10. 2008 TCU | Improvement: +15.7% | Where Michigan Would Rank: 43rd
Now, it's worth noting that the 2008 Florida defense made their significant improvement the year after new Michigan coordinator Greg Mattison left. When Mattison had experience at his disposal, great things happened, but his final Florida defense was neither experienced nor good.
Generally speaking, a team that improves defensively in a given year, improves by about 5.3% in terms of Def. F/+. Such an improvement would only raise Michigan to around 90th in the Def. F/+ rankings, so the odds are good that any gains this year will be modest. And even significant gains would only place them at an above-average stature. But hey ... there really is nowhere to go but up.