If you’re familiar with scorecasting (and you should be), then you know that one of their arguments is that not only is referee bias the main determinant of home-field advantage, but that based on their data it was the ONLY determinant of home-field advantage.
At least in 1-A college football, this does not appear to be the case. As you can see in the above table, there is a nearly across the board trend towards the home team doing better the further the distance between the two schools.
While it is true that this effect is not huge, it is overall noticeable. Across 1-A, the difference between the win % for home teams within 500km and those 1000+km away is about 5% (59.3% vs 64.3%) when the league records are within 1 game of each other, and about 3% (91.6% vs 94.8% and 10.6% vs 13.3%) when they are not.
Interestingly, this effect is minor when you compare distances of 0-500km to distances of 500-1000 km. It is only when the distances are larger than 1000km that there is a large impact.
That may explain why, historically, homefield advantage hasn’t been as big a deal in the relatively compact SEC compared with other conferences.
Also not surprising is that the travel factor is negated by talent level.
… The bigger the talent gap, the smaller the absolute difference in upset rates between home and away, but the larger the relative difference (home upset rate / road upset rate). The same thing applies when factoring in distance.
When the teams are 1 game different, the road team gets an upset 36% of the time, and the home team 43% of the time (a 7% gap). Within 500km, it’s 35.2% vs 40.0% (a 5% gap), but for 1000+km, it’s 36.4% vs 45.6% (a 9% gap).
And when the teams are 2+ games different, the road team gets an upset 6.7% of the time, and the home team 11.0% of the time (a 4.3% gap). Within 500km, it’s 8.4% vs 10.6% (a 2.2% gap), while for 1000+km, it’s 5.2% vs 13.3% (a 8.1% gap, but almost TRIPLE the upset rate).
Here’s one surprise I did find.
It’s been said in a few places that the SEC has lower home winning rates than other leagues, and the data bears this out (though it’s worth noting that the SEC had one of the highest home winning rates in 2010, so it MAY be changing).
Georgia by itself may have been a significant contributor to that trend (if it turns out to be a trend, that is), considering it lost three conference games in opponents’ stadiums last season and had only lost a total of five such games in the eight seasons previous to that.