FPI

Info on FPI calculations is here: https://www.espn.com/blog/statsinfo/post/_/id/122612/an-inside-look-at-college-fpi

With relevant info below

In the preseason, these components are made up entirely of data from previous seasons, such as returning starters, past performance, recruiting rankings and coaching tenure (more on the preseason component below). That information allows FPI to make predictions (and make determinations on the strength of a team’s opponents) beginning in Week 1, and then it declines in weight as the season progresses. It is important to note that prior seasons’ information never completely disappears, because it has been proved to help with prediction accuracy even at the end of a season. Vegas similarly includes priors when setting its lines.

So not just the previous single season, but multiple and other data as well (recruiting returnees etc), with more specifics of that below if you want to get into it

Preseason ratings historically have their flaws, but ultimately they allow for an opponent adjustment after Week 1 and are a great tool to preview the season. As noted, there are four components to the preseason rating: prior performance, returning starters, recruiting rankings and coaching tenure.

— Prior performance is built off the framework of expected points added. The most recent year’s performance is by far the most important piece of information powering preseason FPI, but three more years are added to measure consistency and account for outliers in performance. The most recent year counts almost twice as much as the three years before it.

— Returning starters on offense and defense, with special consideration given to starting quarterbacks or transfer quarterbacks with starting experience, is the second piece of information powering preseason FPI. Because starters interact with other inputs, it’s not as simple as saying an extra returning starter is worth one point. Nonetheless, a starting quarterback is worth about 3.3 points per game to a team returning an average offense (all else equal), and a transfer quarterback is given half the weight of a starter.

— FPI uses four recruiting services — ESPN, Rivals, Scouts and Phil Steele — to measure the talent on a team’s roster and add an additional piece of information about which teams are on the rise. The addition of recruiting has been a controversial piece of FPI, but it’s worth noting that it is a very minor component that helps with prediction accuracy.

— Coaching tenure is primarily a way to capture the addition of a new head coach. With all else equal, a team’s predictive offensive, defensive and special teams ratings will regress slightly to the mean with the addition of a new coach.