The 10 hardest 2021 schedules, per SP+ SOS ratings:
1. Arkansas
2. Nebraska
3. Auburn
4. Georgia Tech
5. Purdue
6. Michigan
7. Indiana
8. LSU
9. Colorado
10. Penn State

An avg top-5 team would produce a win% of 0.782 (~9.3 wins) vs. Arkansas' schedule.

— Bill Connelly (@ESPN_BillC) August 24, 2021