MLS Fantasy Boss A Fantasy MLS Community
With unlimited transfers, match ups are more important than ever. So how do you evaluate match ups? Especially if you’re only an aspiring Armchair Analyst and not yet the real thing. The answer? The expected goal (xG) rankings!
What are expected goals (xG)
The idea behind xG is simple. Every shot has probability of scoring based on the position on the field and the game situation, based on giant databases of shots from years and years of data. Then at the end of the game all the xGs from the individual shots are added up to generate the team’s xG for that game. This metric is a useful measure of the teams overall attacking or defending play, more so than just looking at how many goals a team has scored or allowed. If you’d like to learn more, there’s a nice video by MLS to explain further:
How to use these rankings
The rankings below use the xG metric to rank the match ups each week to help you determine which teams you should try to choose your attackers or defenders from. Each teams score is an average of their xG/g and their opponent’s xG/g separated out into offense/defense and home/away match ups. For example, if Atlanta plays NYCFC at home. Atlanta has an average home xG/g is 1.62 and NYCFC’s has an average away xG/g allowed is 0.96 for an offensive xG score of 1.29 xG. The reverse can be done to calculate their defensive score for this week. The game by game xG numbers are taken American Soccer Analysis.
https://www.americansocceranalysis.com/by-game-2018/
Week 8 Offense xG Match Up Rankings
This week there are two sets of rankings. The Home/Away Offense score is the standard rankings you’ve been used to where I use the teams’ specific home and away xG numbers. Early in the season, the rankings have been poor due to a small sample size. The Average Adjusted Offense Score tries to combat the small sample size by averaging all home and away xG into a single offense and defense score. Then I adjust the the xG values based on the average difference between home and away offenses and defenses. Hopefully this will improve the rankings as we wait for more games.
Week 8 Defense xG Match Up Rankings
