And here’s the real trend within the trend. The two leagues most responsible for the dip in home-field advantage are the Big Ten and Big 12. Look at the win percentage of home underdogs in those two leagues.
Home field advantage, when quantified in terms of points, means the difference in how a team performs on the scoreboard at home vs on the road against an average foe.
Not necessarily wins and losses.
Alabama has virtually no home field advantage because they play so well on the road.
Arizona has a huge home field advantage because their results are markedly different vs conference foes on the road vs conference foes at home.