Alabama Crimson Tide fans, like every other college football fanbase, wonder about the ESPN FPI. The algorithm is closely held by ESPN. As a predictive model, its primary goal is not ranking all the teams, but rather to predict game outcomes.
As the season progresses, more data is available on each team. In the second half of the season, the accuracy of game predictions should go up. More simply stated, a preseason predictive model is a work in progress. Using any algorithm or mathematical system, five-plus months in advance of a season is problematic.
The ESPN FPI rankings do provide a legitimate early assessment of Strength of Schedule (SOS).