The average college football homefield is 3...I would say there are 20-25 homefields that would grade out as a 4 for the HFA.
Ten, Tex, A&M, FSU , Army,UCLA, Was, Wisc,USC, Penn St, Okl, NEb, Mich, Mich St,LSU, Ga, Fla, Clemson,BYU,USC, Aub, Ala, ASU...all would have a homefield of 4 IMO...I'm sure there are a few more