From my understanding, the Men's basketball rotations for the 20-game conference schedule are based on 6-year cycles....and 2018-19 was the first year this was adopted.....so running through the 2023-2024 season:
Three in-state rivalries played every year (home/away):
Illinois/Northwestern
Purdue/Indiana
Michigan/Michigan State
Regional Rivalries - 10 times in the cycle:
East (Maryland, Ohio State, Penn State, Rutgers)
West (Iowa, Minnesota, Nebraska, and Wisconsin)
All others - 9 times in the cycle
Each team plays 120 games in the cycle - Purdue would play Indiana 12 times and everyone else 9 times, and so on. Maryland would play its three regional rivals 10 times, and everyone else 9 times, and so on.
Purdue and Michigan are 9 times this cycle (2019 - @ Michigan; 2020 (home/away). I think these are supposed to alternate each year, so based on that, it would seem like next year would be a single game @ Purdue). It would take two cycles to even out for every team/opponent home and away I think. Life in the Big Ten (14?). Don't blame me, I'm a rag-top man.