Is Being At Home Really an Advantage?

Test 1 · A Naive Comparison

Raw score differential - average(home score − away score) across non-neutral games, no adjustment for team strength.

Test 2 · Accounting for Team Strength

OLS regression of point differential on the home/away indicator and the gap between the two teams' ratings entering that game. The home/away coefficient is what's left over once team quality is already priced in - the real, adjusted home advantage.

CFB R² = 0.273 · CBB R² = 0.433

Test 3 · Neutral-Site Sanity Check

Same regression restricted to neutral-site games only, where the intercept should land close to zero if the model is behaving correctly - there's no true home team to give credit to.

Test 4 · Statistical Likelihood of the Advantage

A cluster bootstrap (resampling by team, 95% CI) and a permutation test on the Test 2 coefficient - whether the adjusted advantage is actually distinguishable from zero, not just a single lucky regression fit.

CFB 95% CI [-10.57, 7.94] · p = 0.9830
CBB 95% CI [2.96, 4.85] · p = 0.0000

Test 5 · Collinearity Check

Correlation and variance inflation factor (VIF) between the home/away indicator and the rating-difference term - rules out Test 4's result being a modeling artifact rather than a genuine finding. A VIF near 1.0 means no meaningful inflation.