@betarhoalphadelta is possibly the only other poster who is enough of a stats geek to appreciate this but I was curious so I did some looking.
If you look at the last 80 years of tOSU/M:
- Ohio State leads 23-15-1 in Columbus
- Michigan leads 20-18-2 in Ann Arbor.
The 2020 game was not played but Ohio State went to the NCG that year and Michigan completely sucked so if we treat that as a tOSU win then give Michigan a win for the 1992 tie in Columbus and conversely give tOSU wins for the ties in Ann Arbor in 1973 and 1949 you get this:
- Ohio State leads 24-16 in Columbus
- Tied up 20-20 in Ann Arbor
So the HFA difference averages one game every 20 years. Dividing the above into four 20-year segments, the average is:
- Ohio State leads 6-4 in Columbus
- Tied up 5-5 in Ann Arbor
It is even less of a factor in the Oaken Bucket game, over the last 80 years:
- Purdue leads 27-12-1 in West Lafayette
- Purdue leads 25-14 in Bloomington
The 2020 game was not played but Indiana was a LOT better than Purdue that year so lets assume that IU would have won that game in Bloomington then give the 1958 tie in West Lafayette to Indiana as well, you get:
- Purdue leads 27-13 in West Lafayette
- Purdue leads 25-15 in Bloomington
The HFA difference is only two games or one game every 40 years.
