Expected Goals are a useful metric over the longer term, because any good xG model will see its players regress back to the mean over time. It means that are certain points of a season we can assess a player's goal total, compare it to their xG total, and identify players who are either over or underachieving the model.
EXPECTED GOALS (xG) assesses the quality of a shot based on several variables such as assist type, shot angle and distance from goal, whether it was a headed shot and whether it was defined as a big chance. From there that shot is assigned an xG score and the cumulative total of these scores provides a team's xG for a match.Stats Definition
See the tables below and be sure to click the related article for more reading from James Tippett's box entitled the Expected Goals Philosophy.
This data gathered from the Understat model, which can be found here.
Poor David McGoldrick. Sheffield United fans adore him for his all-round leading the line performances but it's ridiculous he hasn't be able to convert at least one chance this season. It will turn for him eventually if he keeps getting into the right areas. Elsewhere Wood and Jota's numbers should probably be a little better, so are worth keeping an eye on.
Luuk De Jong's troubles in front of goal have been much highlighted, and his club Sevilla would be much better off than their already good position if they could find a striker who could score regularly (Chicharito looks set to leave, while Munas Dabbur has already gone to Hoffenheim). De Jong's record, unfortunately, has become somewhat of a running joke.
No huge errors in the Bundesliga, though Kamada and Burgstaller will both be disappointed that they haven't been able to get off the mark for the season.
There are a few high-profile names here, including alleged Spurs target Piatek and Lorenzo Insigne. It should be noted that both are playing in teams massively underachieving at the moment, and though their numbers aren't McGoldrick territory in terms what he should have scored, they are still below what should be expected.
Jonathan Bamba can count himself unfortunate he doesn't have a few more on his tally for a talented Lille team.