Stats review: Creation of chances and efficiency

We are almost halfway through the Superliga season. This means that match data is piling up to a useful sample. In this first look at stats from the Superliga season we will focus on creation of chances and efficiency. A lot of debate has been going on in Great Britain as of how to use match data to forecast future matches. This debate has increasingly moved towards focusing on shooting statistics.

In Denmark shooting statistics are readily available from Superliga.dk. We have collected stats from every match in the first 15 rounds and we will here provide an overview of what we found. We will start with the total shots statistic:

A necessity for winning matches is the ability to create chances. The total shots statistic is a natural proxy for this and the statistic is obviously able to predict the current position to some degree (many shots equals top half position and vice versa). You have to keep in mind that the difference between 3rd and 11th position is only three points. This statistics points out some interesting things:

• The Copenhagen teams (FC Copenhagen and Brøndby) are creating tons of chances, but nine points after league leaders, FC Midtjylland. If they can keep this up, they will be a real threat for FC Midtjylland.
• Based on this statistic the two relegation spots should go to Viborg and AGF. Especially Viborg’s lack of shots is startling. They are 25 shots between number 11 and almost 100 shots behind FC Copenhagen. Viborg fans are probably also pretty satisfied with the clubs current position.
• The two underperformers based on their chance creation are FC Nordsjælland and SønderjyskE. While momentum has shifted for FC Nordsjælland, SønderjyskE are still looking for a way out their problematic situation. This stat should be a motivator: based on chance creation, they do not deserve relegation.

An obvious discussion is whether total shots are the best measure for chance creation. If the shots are hopeless long-range efforts founded by own inability to break down the opponent’s defence, it will give a biased result (favouring poor teams). Since stats based on origin of shot are not available at Superliga.dk, we will go for the second best option: total shots on target. Total shots on target are the chances that have an actual chance of resulting in a goal. A shot off target could never be a goal. In this sense, the statistic is probably a better proxy for chance creation. Here are the stats through 15 rounds:

This statistic provides some different conclusions:

• Brøndby is still at top with a huge and impressive margin, while FC Copenhagen are obviously not as good at creating chances. FC Copenhagen must either have poor finishers or make many attempts from positions where it is difficult to get the ball on target.
• AaB and FC Midtjylland’s current position in the top is fair based on their chance creation.
• SønderjyskE’s position at the bottom now makes more sense. The possible explanations for their drop in chance creation are the same as the above mentioned for FC Copenhagen.
• Viborg is still at the bottom. The gap is not that big anymore though, signalling that the few attempts they have are actually quite big.
• Esbjerg (well, maybe along with Brøndby) seems to be the biggest underachiever based on this statistic.

This was a look on chance creation. Lets move on to the next focal point: efficiency. We define this as the scoring percentage and calculate this as:

Scoring%=Goals/Shots on target

At first thought this appears like a very important statistic, but in the quest for forecasting future performance it is actually of minor importance. According to Grayson this statistic regresses to the mean over time, which means that the statistic is mainly based on luck with only a minor difference between good and bad teams. With this in mind we present the current numbers:

This statistic makes some explanations:

• Viborg’s current league position is based on their crazy efficiency. Thomas Dalgaard is league top scorer with ten goals and his achievement is even more impressive when considering the fact that he is playing for the team that creates the least/second-least chances (based on which statistic you use). Although Dalgaard is a talented finisher it is highly unlikely he can keep up his high scoring average if the low chance creation continues. Viborg have for instance twice the scoring efficiency of Brøndby, which in no way could be a steady state: this difference will diminish.
• AGF fans should also be slightly concerned. If it had not been for their high efficiency, they could have been in a critical position.
• For Esbjerg the result is surprising. They create many chances and exhibit a high efficiency, but their position is bad. The explanation will follow in our next stats review.
• For fans of FC Nordsjælland, SønderjyskE and Brøndby they can find some positives in their teams low scoring percentage. If we use the findings of Grayson, this percentage should move toward the mean (currently 28%). If this happens we should see these teams scoring more goals and also win more matches.

A little note at the end: Grayson finds in his examination that the average team has a scoring percentage 21,8%. In our sample the average is 28,01%. This indicates that the way of measuring shots on target by Superliga.dk is very likely to be different than for the sample of Grayson. We do not believe this pose a problem for our analysis as long as Superliga.dk is consistent in their way of measuring.

We hope you liked this review and it gave you some interesting insights. We will bring an analysis of the defensive side of the Superliga in the coming days.