I believe you've missed the point. The average HFA this season is 2.47. If you look at the S&P+ rankings you'll see the lines at sportsbooks mirror what Connelly has put together. IE: UGA at 20.0 right now, UK at 8.5 for an 11.5 differential. Home field advantage puts the game at UGA -8.5. It's three points there. Bama is ranked according to S&P+ 26.3 with LSU at 12.7: that would give us Bama -13.5. The spread is higher. In a sense, eliminating the HFA. Another example: USC coming in at 3.5, Ole Miss at 5.3. There's a two point differential and it's listed as a PK the last time I looked. FWIW, Sagarin ratings mirror the spreads as closely as Connelly's rankings.
Are Sagarins still as bad as they were growing up. Yeah I checked some numbers usually within a couple shows Bama should be 17 on neutral and 3 for hfa which is 14. Dead on the number.
I look at his rankings all year but pay much closer attention to them after the sixth or seventh week of the season. It's pretty good early on in terms of mirroring the spread, but some has to be taken with a grain of salt. IE: Teams that are opening up with four OOC games before hitting conference schedules. Where?