With the second half of the Eredivisie just a few days away, this may be the right time to refresh our memory of the current state of affairs in the Eredivisie. This post will try to do that by plotting the teams’ offensive and defensive performances. Drawing on earlier posts on this same subject, teams will be evaluated regarding their amount of goals scored/conceded and their rate of converting/stopping goal scoring chances. Data come from Infostrada Sports, who are well worth a follow on the twitter handle @InfostradaLive. Please note that, in line with earlier data used on 11tegen11, blocked shots are not included as goal scoring attempts.
With an average of 3.29 goals per game, this 2011/12 season has been one of the most entertaining ones that the Eredivisie has produced, if high scoring football games mean more entertainment to you, that is! No other season in the past 28 years did produce so many goals per game, and the current season is on its way to break the 2010/11 number of 3.23 too. In comparison with other leagues in Europe, the Eredivisie sees significantly more goals per game than the Serie A (2.47), Bundesliga (2.86), La Liga (2.60) and Premier League (2.80) do.
Let’s first look at the offensive end of the teams’ performances. The next graph will plot the teams according to the amount of chances created and the conversion rate of those chances.
Teams in the upper right hand corner are exactly where they want to be, creating an above average number of shots and converting them well too. This holds true for PSV, Ajax, Twente and AZ, while Heerenveen does quite well mainly due to their efficient conversion.
Teams in the lower left quadrant disappoint both in creating and finishing chances, which is most notably the case at Excelsior. Both VVV and De Graafschap mainly create too few chances, while N.E.C.’s and RKC’s problems lie in the conversion of chances created.
In the upper left, teams with an adequate number of chances, but a problem in conversion can be identified. This is the case at Groningen, while also Feyenoord could do with an improvement in conversion, which would shift them to the right among the title contenders. Problems at Roda and, to a lesser degree, Utrecht are more in creating chances than in converting them.
Considering the fact that most teams are more of less found along an imaginary line from bottom left to upper right, which represents a correlation between the amount of chances created and conversion, Roda’s lower right position is quite an outlier. Their conversion of 0.284 is second by only the tiniest of margins to Heerenveen and AZ, while their 11.2 chances per match is only 13th out of all 18 Eredivisie teams.
The defensive performances are plotted along the same lines. The vertical axis represents the number of chances allowed, while the horizontal axis represents the conversion rate of chances allowed.
Ideally, teams would want to find themselves where Twente and AZ are, limiting both the number of chances and the conversion rate of their opponents. Vitesse, on the left side of the diagram, draw heavily on reducing their opponent’s conversion rate, and still allow more shots than the average Eredivisie team. This suggests (though does not prove) an excellent performance by returned goalkeeper Piet Velthuizen.
The upper right hand is where teams with defensive trouble would be found. De Graafschap and Roda mainly suffer from failing to stop shots from going in, whereas Excelsior and VVV allow roughly 7 and 6 shots per match more than the average team does.
Outliers in the bottom right corner are Ajax, and to a lesser extent Groningen, who successfully limit the number of shots on target, but suffer from a high conversion rate by their opponents, suggestive of (but again not proof of) a below-par goalkeeper performance. Interestingly, both teams changed their goalkeepers compared with last season, Groningen voluntarily by strangely benching Luciano (although he has featured again in the previous two matches) and Ajax involuntarily after the departure of Stekelenburg. Last season’s numbers would have put Groningen (13.9 shots conceded ; 0.105 conversion) just inside the desired left lower quadrant and Ajax (9.8 shots conceded ; 0.090 conversion) well in there.
In the end
A few simple diagrams have seen us updated on the performances on team level in the 2011/12 Eredivisie so far. With the competition finally getting underway again next weekend, these indices will serve as a benchmark to compare the performances in the second half of the season.