Summer of Stats: Team Expected Goals

Welcome to another daily article in the Summer of Stats. Today's topic is the first team stat of the summer! I already talked about Individual Player xG, which is defined by Mark Carey of the New York Times as, “determining the likelihood of a shot being scored based on various factors, taken from the moment before the player shoots. These factors may vary depending on the statistical model, but include the distance to the goal, angle, shot type, and other contextual factors. Each shot is then given a probabilistic value, representing how many times that shot is likely to be scored based on similar shots. For example, a shot with a value of .3 goals is likely to be scored about 3 out of every 10 times.”  

However, today I'll be covering Team Expected Goals, which is the same stat as Individual xG, but takes every player’s xG over the season, and adds it into one stat that shows how well a team as a whole produces offensive chances. 

In Major League Soccer, the San Jose Earthquakes lead all teams in xG with a collective 45.9. Second place is Nashville SC with 42.6, and in third is Orlando City SC with 41.2.

St. Louis City SC sits in 20th with 30.7. Which is interesting because in Goals Scored, City is 27th with 22 goals. This difference highlights St. Louis’s troubles with scoring, as according to xG, they’ve had quality chances, but have failed to score on many of them. 

Thank you for reading yet another installment of the Summer of Stats!