Really interesting. What’s the preseason number based on? Is that mostly expected strength of schedule? I wonder what it means to get worse over the year? We played worse than expected or our opponents did or both?
The preseason number is based on recent program history, number and quality of returning players, and high-profile additions (I think it's top 50 recruits and D1 transfers). It's a bit of a black box, but they've performed extremely well in the years since Ken has been posting them.
For example, Haith's first team returned 70% of their minutes and the top 4 players from a team that finished the previous year ranked 82nd. Based on that information, the team was projected to be the 48th best team in the country. Based on actual results they played like the 85th best team in the country.
The next year, they returned 80% of their minutes and basically the entire roster. Based on that information, they were projected to be the 47th best team in the country. They finished 65th.
In my opinion, the within-season trends point to a team that didn't meet expectations based on their personnel. New players weren't as good as expected based on previous recruiting and they didn't improve as much as expected from year-to-year. When it happens every year for 5 years, that's pretty damning evidence against a coach imo.
The other thing to remember about KenPom is that it's designed to be purely predictive. One of the greatest benefits of predictive metrics is that they're independent of schedule because all of the context has been adjusted for. It's a difference of team quality vs. team resume.