An early look at performances in the Serie A

In the third part of our miniseries, the focus shifts to Italy for the Serie A. After failing to drop a single point at home last season, Juventus currently haven’t dropped a single point in any of their six matches. Like in the Bundesliga, the title run might not be that contested, but behind the boys from Turin, all sorts of excitement and unpredictability arises.

 

Good-Lucky

Using the recently explained Good-Lucky matrix, in a format adopted from Benjamin Pugsley, we can easily scan the league for the best performance teams (horizontal axis) and the most efficient teams (vertical axis). Anyone into football analysis will know that being highly efficient lasts only so long, and PDO levels tend to revert back to normal before you know it. Depending on team quality, normal is a PDO of 980-ish for poor teams and 1020-ish for good teams.

Good - Lucky Matrix Serie A 2014-15 14 oktober 2014Like Bayern in Germany and Chelsea in England, Juventus dominate the Good-Lucky graph, but mostly so on the ExpG axis, which is a good thing for them. With an ExpG-ratio of 0.767 they set an unprecedented dominance.

Behind them is an interesting group of eight blue-ish teams, who seems clearly separated from the rest of the bunch. I write interesting, because apart from Roma and Sampdoria, this bunch had been more or less unfavourable in PDO. The best bet for PDO issues to resolves, and that means we should expect the like of Napoli (7th in the table) and Lazio (8th) to put up a good chase of 2nd placed Roma and 3rd placed Sampdoria, whose outcome seems partly PDO fueled.

Although Milan (5th in the table) would be deemed in less deep trouble than their rivals Inter (10th), it seems to be a matter of time before the ‘nerazzuri’ will catch up with the ‘rossonero’.

Down the ExpG axes it’s Chievo who find themselves in most trouble, with early season surprise package Udinese (4th in the table) the most likely candidates for a winter depression. Sassuolo, Parma and Palermo illustrate the fact that PDO rules early in the season, as these bottom three in PDO terms are also bottom three in the table with 3 points from 6 matches.

 

Points per Game

In the Serie A, just like in the Bundesliga, the connection between performance and points is quite direct. Holding a perfect 3 points per game spot high on top are Juventus, while this graph illustrate future drops and rises.

It’s quite easy to spot what’s going to happen at Udinese and Verona, who hold more points that their performance so far justifies. The reverse is true for Cagliari, and in decreasing order Parma, Palermo and Sassuolo.

ExpG-r vs PPG by team Serie A 2014-15 14 oktober 2014

Predictions

Here’s the ‘sticking my neck out’ part of this mini-series. Using ExpG as a basis, a pretty straightforward model can simulate the remaining part of the season and come to predictions for the final league table. I figured it would be more fun sharing these from time to time, for various leagues, and see what we can learn along the way towards the end of the season.

For this model I’ve limited ExpG to 11v11 or 10v10 situations, filtered out blocked shots (since shot blocking is a skill), filtered out penalties (since they are distributed pretty random and skew the numbers a fair bit) and filtered out rebounds. Furthermore, I’ve regressed the ExpG towards last season’s numbers, based on the R2 between ExpG’s on each particular match day to ExpG’s at the end of the season.

Without further ado, here’s the graph of predicted points, along with a box plot showing the spread and most likely number of points for each particular team. Enjoy!

Boxplot projected league table Serie A 2014-15 14 oktober 2014

3 thoughts on “An early look at performances in the Serie A

  1. raffaele

    Very interesting. I had seen your work on the other leagues and I was on my way to try to apply it to Serie A (not with ExpG, though, ’cause I don’t have such refined data). But you’ve done it yourself, that’s great.

    To me one of the most interesting issue will be to see how the season plays out for Genoa and Verona. Last year both team had (per my calculations using Footbal-Data.uk’s data) pretty high PDOs: 1036 for Genoa, 1090 for Verona.

    By looking at other metrics like TSR o SoTR, I was expecting them to regress to the mean pretty quickly: Genoa, for instance, finished the season with a TSR of 0.383 and a SoTR if 0.419: no other team in the last 9 seasons of Serie A, I’m going by memory here, escaped relegation with such numbers.

    In both cases, though, there was no significant regression and their final points far exceeded their value as measured by TSR and SoTR. So I was expecting a regression this year, but so far did not happen. So I’m very curious to see what happen. It could also be that Gasperini and Mandorlini (the coaches) know something that we don’t… 😉

    Reply
    1. 11tegen11 Post author

      That’s very well spotted!
      Genoa are indeed a perfect example of the limitations of traditional metrics like TSR and SoTR. Escaping relegation with the league’s lowest TSR of 0.393 (in my data at least)

      The difference between TSR and SoTR already explains part of the picture. Genoa’s SoTR is higher than their TSR because they create significantly better quality chances than they concede. I haven’t seen them play (can’t see them all…), but I guess their style is aimed at quality rather than quantity of chances.

      Genoa’s average ExpG per shot created is a league high 0.114, which is nearly 2 percentage points (or 17%) better than the Serie A league average of 0.098 last season. They conceded shots of 0.098 ExpG per shot, or average quality.

      If you consistently create better shots than you concede, TSR is going to underestimate performances.

      Reply
  2. raffaele

    Thanks, that’s really good to know (that’s why I wish I had access to some Opta-like data!).

    The case of Genoa has been a thorn in my side for quite a while and your metric does a very good job in explaining why they consistently outperforms their TSR and SoTR.

    I tried to find an explanation by adding in some data on shots taken from inside the the penality box and from the 6 yards box that I found on the Internet. But, even if adding this nuance projects Genoa better than TSR or SoTR, it still cannot grasp why they manage to be a decent team while being regularly outshot by opponents (even if in this season that happens less).

    If I manage to squeeze out some time I’ll try to ses if applying James Grayson’s recently developed “Team Ratings” does Genoa some justice.

    By the way, I haven’t seen Genoa a lot so far but, yes, the impressoin is that they definitely try to produce good quality shots.

    Reply

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