Everton forward Richarlison is the player within Europe's top five leagues who has underperformed the most in comparison to his Expected Goals.
The Brazilian has an xG of 4.2 over his appearances in the Premier League in 2020/21, but has scored just once, leaving him with an xG difference of +3.2.
Also with a difference of +3.2 is Dusan Vlahovic of Fiorentina, but he has played fewer minutes than Richarlison this campaign.
PSG star Neymar also features in the top 10.
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 at 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
The purpose of identifying these players is not to suggest that they are poor finishers or are having bad seasons. On the contrary, the fact that these attackers are regularly finding themselves in good positions to score means, over time, they will eventually start hitting the target.
Getting into the position to score goals is one of the hardest skills in football and so having a high xG but low goal total is much less worrying than high minutes, low goals and a low xG. That suggests more of an underlying problem.
UNDERPERFORMING XG: TOP FIVE LEAGUES
Player Goals v xG
|#||Player Name||Team||⚽||xG||xG Diff|
|4||Kevin De Bruyne||Man City||2||4.8||+2.8|
Kevin De Bruyne is normally the chief assist maker for Manchester City, but as displayed by the table above he should have scored more himself this season. His penalty miss in the crucial Premier League clash against Liverpool gave him a significant boost in xG, which stands at 4.8 so far against just two goals scored.
One player who hasn't scored at all this season is Kevin Lasagna of Udinese. The Italian forward has an xG of 2.5 but hasn't been able to open his tally in Serie A from the chances created yet.
PSG tend to create plenty of chances, and there is evidence of wastefulness from Neymar as the Brazilian superstar has scored just three goals against an xG of 5.3.
He has actually outscored himself in the Champions League compared to his duties in Ligue 1 despite playing fewer matches.
What underperforming xG means
Underperforming xG is a small sample size is not necessarily a bad thing. Indeed it means that a player - like Richarlison here - is regularly working into good positions and optimum places to score from, but isn't quite getting it done.
xG does mean that - theoretically, at least - if a player continues to get into those positions, the chances should fall for them eventually and the goals will come.