Measuring performances in the Eredivisie – Shot Accuracy

Posted on 21 November 2011

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Yesterday’s blog update was the first of a planned three part mini series looking at team performances in the Eredivisie so far this season. With a focus on the amount of shots created and conceded, we’ve got a rough image of the performance of the teams, allowing a closer look in this second part of the mini series. The present update will focus on the quality of the chances created and conceded by looking at the accuracy in terms of the fraction of shots that was on target.

For details on the data used in this analysis please check the ‘data’ paragraph in the previous post, and, when comparing this analysis with other data sources take particular note of the fact that Infostrada does not count blocked shots.

 

Shot accuracy

In order to analyze offensive and defensive performances, this update adds depth to the previous analysis. The quality of the shots created and conceded is presented as the fraction of shots fired on target. The planned third update will focus on the conversion of on target shots into goals, or for defensive performances, the prevention of the opposing team turning their on target shots into goals.

The left-hand table below ranks all Eredivisie teams according to the fraction of shots they fired on target, while the right-hand table ranks teams according to the fraction of shots allowed on target. For your convenience, both tables have been sorted so that teams are ranked in decreasing order of offensive or defensive performance going down the list.

 

 On average 52% of shots was on target, which sees slightly more variance in offensive performance than in defensive performances. Teams spread out from 61.3% to 45.2% according to shots created, and from 46.6% to 60.6% according to shots allowed.

 

Offensive analysis

The top team with regard to offensive accuracy was Feyenoord, who found the target with over 61% of their shots, outscoring the average Eredivisie team by almost 10 percentage point, or overachieving 20% in terms of offensive accuracy.

Another team doing very well in terms of offensive accuracy is PSV, who also create most shots of all teams. A remarkably good score is found at N.E.C., who only occupy the 15th place in the league table, having scored only 12 goals in 13 matches.

At the bottom of the table, Heracles, currently ranked 9th in the table with a decent 19 goals from 13 matches, are found to have the lowest accuracy of 45.2%. This may help to explain their struggle to turn their success in terms of possession (3rd in the league with an average share of possession of 55.3%) into goals (one goal per 34.0 minutes of possession, 10th in the league).

Other teams with disappointing accuracy are top half teams Groningen (14th, 49.1%) and Heerenveen (16th, 47.9%).

 

Defensive analysis

Two teams stick out positively in terms of the quality of shots conceded. Vitesse and AZ allow their opponents to find the target with just 46.6% and 46.7% of shots. Also N.E.C, sticks out positively again, with only 47.6% of conceded shots being on target.

Of the top teams, both Ajax (52.9%) and certainly PSV (55.5%) seem to allow their opponents too much shot accuracy, sticking out negatively in comparison with fellow title pretenders AZ and Twente (49.0%). The worst performance in this department is for Groningen, whose opponents have found the target with over 60% of shots.

 

Combined analysis

Teams doing well in terms of preventing their opponents from finding the target while creating a high fraction of on target shots themselves should move up in the shots table when we replace the ‘net shots’ table with the ‘shots on target’ table.

The net ‘shots on target’ table shows that PSV do enough in terms of the raw net number of chances created to maintain the top position, despite being outperformed in terms of defensive accuracy. Feyenoord leap to the second place, thanks to their excellent offensive accuracy, combined with Ajax’ mediocre offensive and defensive accuracy.

Groningen drop from fourth to sixth, seeing their 6.2 net overall shots turn into only 1.8 net shots on target. NAC lose some ground due to their atrocious defensive accuracy, while both N.E.C. and Vitesse move up slightly in the net shots on target table. The rest of the table remains more or less as it was.

 

In the end

Creating shots and preventing opponents from shooting is one thing, finding the target is quite another. Looking at shot accuracy, and the defensive counterpart ‘accuracy of shots conceded’, allows to see where teams concede ground to their rivals in terms of turning dominance into goals.

The third and final part of this series will put the icing on the cake as we’ll look at conversion, the fraction of on target shots turned into goals, or prevented from going into the goal. While the move from the sheer amount of net shots created to the amount of net shots on target created has helped the insight in terms of offensive and defensive performances, the addition of the performance in terms of conversion will provide the missing piece of the performance puzzle.

This post could never have been created without the support of Infostrada Sports, who’ve provided the data for the analysis.

Posted in: Eredivisie