Wednesday, January 22

Updates To Expected Goal Model



Here at InsideFPL we are on a non-stop quest to get underneath the performances of teams and players in order to understand what’s going on, and from this give you as much information as possible to help you boss bragging rights in your all-important fantasy mini-leagues.

Our ‘Expected Goals’ model and stats are an example of that. Player Statistics like shots and key passes are a very useful and popular indicator of a player’s potential goals and assists. This season we’ve taken this to the cutting edge of football analysis by classifying each shot by position and type and assigning it an ‘expected goals’ value based on typical goal conversion rate for this kind of shot.

The current xG model you’ll be used to from our Player Ratings and which is used to determine our Point Projections was based on last season’s data. Over the last month we’ve gone through the exhausting task of collecting and collating the data from the 2011/12 season too, and with both of these plus the current season data we now have almost a thousand matches and near 30,000 shots to draw from.

To get to the point, with almost three times the data we’ve been able to round out some of the variables and make some improvements to the model. We’ve been able, for example, to nail down an expected goal value for shots from through balls where as previously, without enough data, we had just classed these as normal passes. For reference, through balls are gold dust!

Here’s a look at Expected Goals (xG) vs. Actual Goals since 2011/12 so you can see how accurate an approximation xG is.




With the extra data we’ve also been able to look at some historical trends for player’s shot conversion which will say now will be very important for fantasy football managers.


At the moment we’ve updated our Player Stats for GW22 with the data from the current model. Over the next few days and in time for GW23 we hope to move it all over to the latest model as well as share some of the important insights we’ve found, particularly which players have a strong record of scoring goals for fun.