they do that to help normalize for SoS. for my personal formulas I multiply the raw score by 8%*number of standard deviations the avg opponent is, which would be difficult for you to do unless you have the games separated. Also out of curiousity, is the PPD the yearly point per drive avaerage or the average of every PPD per game?
IIuc, football outsiders already normalizes for SoS for both their FEI and S&P+. They combine them for their "official" rankings in Fplus because they think it gives them a better assessment of actual strength of the units. I also think they use/recommend fplus for prediction, but I could be mistaken.
You're right, that I can't adjust for SoS because I don't look at games or drives individually. I use cfbstats. I download the Rushing Offense, Passing Offense, FGs, Punting, Fourth Down Conversions, and Turnover margin tables against Power 5 opponents.
Drives = sum(Rush TD's, Pass TD's, FG Atts, Punts, Failed 4th, Lost Turnover)
Points = sum(7*(Rush TDs + Pass TDs), 3*FGs Made)
Comparable calculation for D.
So, end of half drives and safeties don't get counted as drives. Also, Defensive and Special Team Scores don't get counted for points.
While not sophisticated, I think that only counting power5 games and only ranking teams that played at least 3 does an alright job in adjusting for strength of schedule. I posted the table comparing my PPDvPwr5 ranking with the AP and Coaches as at least making an argument on its behalf.
The question I was asking in the post to which you responded was whether there was a way of combining raw yards/play and points/drive stats to improve this poor-man's predictor.
