It’s last yrs rating x 66.6% and team £ val x 0.33%
See this link. It means nothing but to serve as a prediction, rather than just an historic view.
It’s an attempt to model a sport which is well none to be difficult to model.
How often do you come away from a match thinking - we were lucky / unlucky?
Compare this to snooker, tennis, rugby cricket etc... much easier to predict. Results are not always based on performance- therefore predictions are difficult.
Can’t be bothered to read it all - but has some funky stuff in there like this ...
“The first, adjusted goals, accounts for the conditions under which each goal was scored. For adjusted goals, we reduce the value of goals scored when a team has more players on the field,2 as well as goals scored late in a match when a team is already leading.3 After downweighting these goals, we increased the value of all other goals to make the total number of adjusted goals generally add up to the total number of actual goals scored over time.
Shot-based expected goals are an estimate of how many goals a team “should” have scored, given the shots they took in that match. Each shot is assigned a probability of scoring based on its distance and angle from the goal, as well as the part of the body the shot was taken with, with an adjustment for which specific player took the shot.4 These individual shot probabilities are added together to produce a team’s shot-based expected goals for that match, which may be bigger or smaller than the number of goals it actually scored.