Serie A Roundup: By the Numbers
How have Serie A teams fared so far this season? We analyze using expected goals (xG), non-penalty expected goals (npxG) and expected goals difference (xGD).
After 13 matches, team positions have been solidifying at the top of the table. Inter Milan and Juventus played a decisive tie at the Allianz Stadium this match-week where the two teams seemed rather happy to share the spoils. Meanwhile, AC Milan and Napoli, who have just fired Rudi Garcia and replaced him with Walter Mazzarri, were able to maintain pressure on the top two with wins over Fiorentina and Atalanta, respectively.
Competition for a Europa League spot has been hotly contested — only 6 points separate Roma in 5th place and Sassuolo in 14th. Roma and Lazio, two direct rivals and regular Europa League contenders, are so far having very distinct seasons. After a rocky start, Roma has finally found their stride, only losing one of their last five games, the loss coming against league leaders Inter Milan. Lazio’s form has shown to be more unpredictable, losing to Genoa at the Stadio Olimpico and going on to beat Napoli away a few weeks later.
In the bottom half of the table, a young Frosinone side (average age 24.8 years) and their big prospect Matias Soulé hope the excitement surrounding their team can lift their form. Sassuolo, led by Domenico Berardi, has slowly fallen further down in the table over the past few years, finishing 8th in 2020 and 2021, 11th in 2022 and 13th in 2023. The team now sits in 14th place, dangerously close to having to endure a relegation battle come spring. On the other hand, Hellas Verona, having stayed in the Serie A on goal difference last year is once again appearing to endure hardship. The Gialloblu are the only team to have registered 4 losses out of the last 5 games.
Irrespective of each team’s form, there is a tendency for some teams to over-perform in front of goal while others underperform. How have these teams fared in their attacking movements? We start off with a simple comparison that helps us visualize how a team performs in front of goal (Figure 1). Empoli, who provided Napoli with a major upset in match-week 12, is an example of an underperforming attacking squad. Empoli, who had only scored four goals in their first eleven matches before this past weekend, reflected a much higher creation rate. Their expected goals average is equal to a goal each game, more than double the tally they had been scoring before this weekend. Therefore, even though they were able to put 3 goals past Consigli this past weekend, they’ll still be wondering how they can improve in front of goal.
Another team that vastly underperforms in front of goal is Udinese, who has only registered 9 goals out of their 15.7 expected goals. For example, in their match against Atalanta, on match-week 12, they registered more than double their rivals xG, yet ended up sharing the spoils in a 1–1 draw. On the contrary, teams overperforming their xG include Fiorentina, Atalanta, Roma and Inter.
Figure 1.
Expected goals has become an important indicator for how effective a team is in front of goal, but it can still bias perception on how well a team is able to create chances. When specifying only non-penalty goals (Figure 2), Udinese’s expected goals decrease by almost 20% given that 2 of their 8 goals this season have come from the spot. Juventus has also been unable to take advantage of their opportunities. The regression line represents the average number of goals a team scores given a certain number of expected goals. For example, Juventus have 20 expected goals which would on average translate to around 22 actual goals, but they’ve only been able to score 20. Given these numbers, they’ll be questioning whether their heavy investment up top has been justified with a below average performance. When penalties are disregarded (Figure 2) Salernitana overperforms the average goals to expected goals ratio, unlike when penalties are included (Figure 1). Although this overperformance is marginal, it still demonstrates how missing a penalty skews the data substantially when understanding how a team performs in open play.
Figure 2.
Expected goals and non-penalty expected goals are a good indication of a squad’s efficacy in the final third, but it’s not always representative of overall form. Figure 3 looks at expected goals difference, meaning the difference between expected goals and expected goals against. What we notice here is that towards the top of the table there is a greater concentration towards the average. Juventus’s expected goals against is lower than the number of goals they’ve conceded. Their low output upfront is being offset by their ability to keep their rivals at bay, suggesting that their title charge is being held up by their back line. However, their rivals Inter don’t just exceed expectations in front of goal, they are also similarly able to limit the number of goals they concede. Inter have conceded 1.8 fewer goals than expected this season, while Juventus have only conceded 0.6 fewer goals than one would expect. In short, Inter are not only better at creating and converting their opportunities, they’re just as good — or even better — than Juventus at protecting their own net.
In the bottom half of the table there are greater deviations from the regression line which is driven by both the difference in ratios of expected goals to actual goals and expected goals against to actual goals against. For example, Empoli struggles in front of goal, sure, but they also allow many more goals than expected. Their expected goal difference is -5.2 while their actual goal difference is -17. If they are able to close the gap between those two stats, then they’ll most likely be clear of any relegation battle come spring.
Figure 3
These simple statistical comparisons provide a good analysis of how teams could project to improve. Teams such as Empoli and Cagliari could improve their defensive capabilities hopefully to marginally gain points that will keep them away from the relegation battle. Empoli also has space to improve upfront as they create sufficient chances to increase the number of goals they score each match-week. At the top of the table, Inter has solidified their position by taking advantage of the chances they create while halting their opponents offensive abilities. Juventus has space to improve in front of goal. if they want to be considered serious title contenders then they’ll need to start over performing their xG. After the sacking of Rudi Garcia, Napoli will look to strengthen their defense capabilities while awaiting Victor Osimhen’s full recovery, hoping it will improve their productivity in the final third.
