Something odd about the football schedule. Wisconsin is in the other division; our Big 10 West opponents each year, in theory, should rotate through. But we play Wisconsin for at least six years straight. As far as I know, the only "protected rivalry" is Indiana vs. Purdue.
Here are the dates we play Wisconsin, with our other Big 10 West opponents in parentheses. You'll notice that over this six-year period, we play Illinois twice; Iowa twice; Purdue twice; Minnesota twice; Nebraska twice; Northwestern twice; and Wisconsin 6 times:
Oct 1, 2016: @Michigan 14, Wisconsin 7 (Illinois, @Iowa)
Nov 18, 2017: @Wisconsin 24, Michigan 10 (@Purdue, Minnesota)
Oct 13, 2018: Wisconsin @Michigan (Nebraska, @Northwestern)
Sep 21, 2019: Michigan @Wisconsin (Iowa, @Illinois)
Sep 26, 2020: Wisconsin @Michigan (@Minnesota, Purdue)
Oct 2, 2021: Michigan @Wisconsin (@Nebraska, Northwestern)
Given that there are 18 games and 7 Big 10 West opponents, I'd expect there to be more of a 2-2-2-3-3-3-3 split.
Does anyone have the answer?
UPDATE: Here is Wisconsin's non-Michigan Big 10 East schedule over the same period. MSU twice, OSU twice, Maryland twice, Indiana twice, Rutgers twice, PSU twice, Michigan 6 times:
2016: @MSU, OSU (played PSU in championship)
2017: Maryland, @Indiana (played OSU in championship)
2018: Rutgers, @PSU
2019: MSU, @OSU
2020: Indiana, @Maryland (also plays Notre Dame)
2021: PSU, @Rutgers