Set piece analysis: Expected goals on target (xGOT) in Eredivisie 21/22
Whilst we are already a few rounds into the Eredivisie 22/23 season, it’s still very interesting to have a look at the 21/22 season. I’m particularly fond of set piece, attacking corners in particular, and how teams try to generate chances from them. In this analysis I will try to do exactly so.
In this analysis, I will attempt to have a look at the shot locations of each team playing in the 21/22 season with data from Opta and look at the zones that give the great threat and/or chances for the attacking side. These will be done via data visualisations with expected goals on target.
The distinction is made between expected goals and expected goals on target (xGOT). This has been done to an idea of which players do have an impact of scoring and actually forcing the goalkeepers to a save or defensive action.
Contents
- Theoretical frame: data
- Theoretical frame: methodology and tools
- Most impactful teams
- Teams: Expected goals on target per zone
- Teams: successful routines per most successful zone
- Final thoughts
Theoretical frame: data
For this analysis, data will be used and there are two types of data that are being used.
The first type of data is so-called match data which focuses on different data metrics that are quantitative. They focus on how many times a certain player makes a certain action that’s translated to a data metric. This will be used for the number of corners taken, the shots generated from them, and the goals. This data has been collected via Wyscout’s data and was collected on Saturday 20th of August, 2022.
The second type of data is event data. This type of data focuses on X and Y locations on the field and records an event. We can collect many data events with this type of data, but in this analysis, we only look at the shot locations and the corresponding values assigned to them. We will then look at the expected goals on target that go along with the shot locations. This filters the shots that are blocked and go wide, to suit the impact analysis we are doing. This data has been collected via Opta’s event data and was collected on Monday 15th of August, 2022.
Theoretical frame: methodology and tools
With the data we have collected, we have all shots conducted throughout the season in the Eredivisie 21/22. There are two different tools I will use to do the research for our analysis — because we focus on the attacking corners of each side.
The first tool we use is Tableau and we use this for the quantitative data collected via Wyscout. With this, we can make scatterplots and bar graphs quite easily, and give an overview of how well each team is doing. This can be considered as data that lies on the surface and quickly gives us an idea of how the strengths are lined up. We view everything in metrics per 90 minutes, as that gives a better idea of the average performance in set pieces per each team.
For the shot locations, I use a different tool. The data was collected via Python and in Python, I will use this data to do data analysis and to make the visualisations. These visualisations are inspired by Son of Corner and he has an excellent tutorial here, how to make these visualisations.
After loading all the data in my code, I make sure to filter for a few things. Firstly I filter a team, then I filter only expected goals on target and I make sure the data only looks at shots as a consequence of a corner. After I have done this, I can start with making the visualisations and the data analysis.
Most impactful teams
If we look at the most impactful teams in terms of set pieces, we tend to look at the goals scored, as that is what you try to achieve with it. In the graph below you can see this.
In the graph above you see the Eredivisie teams and the corresponding goals scored from corners. It’s interesting to see that 4 out of the 5 top teams in the League, also feature in the top 4 for corners goals scored in the 21/22 Eredivisie season.
As you can see, we see the percentage of all goals scored with attacking corners. Go Ahead Eagles has the most impact via attacking corners goals with nearly 25%. AZ and Feyenoord score high, but it’s remarkable that more lower placed teams, do have a higher percentage. RKC and PEC Zwolle lacked that impact with 5% and 3,85%.
Teams: Expected goals on target per zone
In this section we are going to look more closely at each team and which zones they targeted — which zone gave the most expected goals on target (xGOT)?
Ajax
In the visual above you can see where Ajax created the most xGOT. 41% of the xGOT in corners has come from the area at the right post. Most of the xGOT is in and around the six-yard area, indicating they want to have high-quality chances of scoring from corners.
AZ
In the visual above you can see where AZ created the most xGOT. 29% of the xGOT in corners has come from the area at the left post, but also 26% at the right post. Most of the xGOT is in the the six-yard area, indicating they have high quality chances there. What’s interesting is that they have xGOT outside the penalty area.
Cambuur
In the visual above you can see where Cambuur created the most xGOT. 57% of the xGOT in corners has come from the area at the left post, but also 25% at the right post. Most of the xGOT is in the six-yard area, indicating they have high quality chances there. What’s interesting is that they have little to know xGOT outside the six-yard box.
Feyenoord
In the visual above you can see where Feyenoord created the most xGOT. 32% of the xGOT in corners has come from the area at the right post, but also 25% at the left post. Most of the xGOT is in the the six-yard area, indicating they have high quality chances there, but they also have 15% in the right side of the penalty spot. The 4% from far out is fascinating.
Fortuna Sittard
In the visual above you can see where Fortuna Sittard created the most xGOT. 29% of the xGOT in corners has come from the area at the left post, but also 17% at the right post and 20% right of the penatly spot. Most of the xGOT is in and around the six-yard area, indicating they have high quality chances there. What’s interesting is that they have xGOT outside the penalty area from the left corner side, as they had shots on target from that area and even scoring from there.
Go Ahead Eagles
In the visual above you can see where Go Ahead Eagles created the most xGOT. 43% of the xGOT in corners has come from the area at the left post. The two zones after that are on the right side of the penalty spot with 17% and 20%. The distribution of the different zones do seem to indicate a difference in delivery.
FC Groningen
In the visual above you can see where FC Groningen created the most xGOT. 38% of the xGOT in corners has come from the area at the left from the penalty spot, but also 29% at the right of the penalty. Most of the xGOT is generated from there and considering the lower percentages higher or deeper, it’s like that the deliveries were outswingers or deep inswingers.
SC Heerenveen
In the visual above you can see where Heerenveen created the most xGOT. 28% of the xGOT in corners has come from the area at the right post, but also 24% right from the penalty spot. What’s also interesting is that 15% of xGOT also comes from the edge of the penalty area on the right, an indication of a deeper play.
Heracles Almelo
In the visual above you can see where Heracles Almelo created the most xGOT. 36% of the xGOT in corners has come from the area right from the penalty spot, but also 34% at the left area from the penalty spot. Most of the xGOT comes from the areas near the penalty spot, but all the other areas do have a lower percentage. They, however, indicate a variety of deliveries.
NEC Nijmegen
In the visual above you can see where NEC created the most xGOT. 49% of the xGOT in corners has come from the area left from the penalty spot, but also 18% at the left post. A significant percentage (12%) comes the area on the left outside the penalty area.
PEC Zwolle
In the visual above you can see where PEC Zwolle created the most xGOT. 43% of the xGOT in corners has come from the area at the left post, but also 14% at the area next to the right post area. Most of the xGOT is in the six-yard area, indicating they have high-quality chances there. What’s interesting is that the area next to the penalty spot on the right, has 14% of the xGOT.
PSV
In the visual above you can see where PSV created the most xGOT. 21% of the xGOT in corners has come from the area at the left post, but also 31% at the area right from the penalty spot. Most of the xGOT is generated in the four areas closest to the goal, with a total of 70% of the xGOT coming from there.
RKC Waalwijk
In the visual above you can see where RKC created the most xGOT. There us one area where the majority of the xGOT is generated and that is the area at the right post with 61% of total xGOT.
Sparta Rotterdam
In the visual above you can see where Sparta created the most xGOT. In all the four areas right in front of the goal, Sparta created a significant percentage of the xGOT. Together it represents 87% of the generated xGOT of Sparta Rotterdam.
FC Twente
In the visual above you can see where FC Twente created the most xGOT. 24% is on the left post and 25%, just outside that area. Deeper in the penalty there has been generated a significant amount of xGOT as well. This indicates the diversity in shot locations as well as diverse strengths in quality shots.
FC Utrecht
In the visual above you can see where FC Utrecht created the most xGOT. 65% of the xGOT was generated from inside the six-yard box, with 20% of the xGOT generated on the right side of the penalty spot. The xGOT is very focused close to goal.
Vitesse
In the visual above you can see where Vitese created the most xGOT. While there are different areas where xGOT is generated, the focus and majority of the xGOT (52%) comes from the area at the left post. There is xGOT on the areas both sides of the penalty spot, but not as significant as we have seen in the left post area.
Willem II
In the visual above you can see where Willem II created the most xGOT. 38% comes from the right post area and 32% comes from the area on the left of the penalty spot. Away from the right post area there is 22% xGOT generated, but those are the most significant areas for Willem II in corners.
Teams: Successful routines per team
Ajax
The zone on the right post and in this instance the near post is the zone where Ajax generated the most xGOT. In this case Martinez comes to that area against Vitesse’s zonal structure and heads the ball towards the far corner.
AZ
The zone on the left post and the near post is the area where the most xGOT is generated by AZ. They attack it well here with runners against a zonal structure and head the ball in goal.
Cambuur
For Cambuur, the most attacked zone is the left post zone, which is frequently the near post zone/area from the left. Against the zonal structure they time their runs well and score a goal from that particular area.
Feyenoord
For Feyenoord, the most attacked zone is the right post. Here it’s illustrated with a corner from the left going deep into the far post zone. Linssen times his run well and heads the ball in goal, with most players going to the front post.
Fortuna Sittard
For Fortuna Sittard, the most attacked zone is the left post. Here it’s illustrated with a corner from the right going deep into the far post zone. Scored by Gladon in the zone between the far post zone and the zone there after.
Go Ahead Eagles
Go Ahead Eagles create many high-quality chances and xGOT from the left post. They didn’t do that with direct contact, but with the second or third contact. This can also be seen in this particular example.
FC Groningen
The zone behind the left post zone is the zone where Groningen generates the most xGOT from. In this example they don’t score from a direct contact from a corner, but from the second phase of the corner — good finish.
SC Heerenveen
For SC Heerenveen, the right post is where most of the XGOT is generated. This header goal illustrates the threat from this particulra zone against Willem II.
Heracles Almelo
For Heracles Almelo, the zones behind the six-yard box are the zones where most xGOT is generated. The initial shot doesn’t go in, but that’s where threat comes from and eventually they score.
NEC
In the zone just behind the left post, is the zone where NEC generates the most xGOT. In this particular corner, the ball goes that particular area just behind the near post and the ball is guided to the far post.
PEC Zwolle
For PEC Zwolle, the left post zone is where they generated the most xGOT — but since they have scored one goal from a corner, here is an example of how they attacked the far post. Something they also do from the right.
PSV
Not always a first contact is needed to score a goal. Even in third phase of the corner, PSV keep on pressing. It’s this particular shot zone, where PSV is very dangerous and can hurt the opposition.
RKC
For RKC, the zone with the right post is very important in generating xGOT. In this corner, they play it deeper and head it towards the near post — where Kramer is situated to slot the ball home.
Sparta Rotterdam
For Sparta it’s all about being as close to the six-yard box as possible. This is also done in this corner, as the second phase leads to a cross into the six-yard box and having someone there increases the chance of scoring.
FC Twente
FC Twente generates the most xGOT in the areas left from the left post, in which they try to shoot. They have people on the left side, making sure they can attack those areas as they are left with space.
FC Utrecht
FC Utrecht like to shoot from the right post, as that is where they generate the most xGOT. With corners from the right, this means that the near post will be occupied and shot from — as you can see in this game.
Vitesse
Vitesse likes to attack and generate the most xGOT from the left post zone. You can see that here in the corner from the left side, meaning the ball will swing into the near post zone — and they score form.
Willem II
Willem II had the most xGOT generated on the right post and that is the zone they like to attack with corners. Here they are in the second phase of the corner and make sure someone has a run into the far post.
Final thoughts
It’s interesting to look at all the data in front of us and do the actual eye test as well. We want to define and look for threats in the penalty area and in this particular article, I’ve tried to use xGOT as an instrument to analyse what the most threatening zone is while having an attacking corner. We could identify which zones that are per team, but does it also mean that those are the areas/zones the team score from? Not necessarily if I’m being honest.
With many teams this corresponds with each other, but it measures where the chance of scoring is highest according to shots on target. It’s only natural that more goals will be scored from there, but it’s not a given. This you can see with lower ranked teams, who aren’t as good in direct contacts.
The idea that lower ranked teams have a bigger percentage of destined places and direct contacts, can be debunked for a part. Yes, usually set piece are a big share of their scored goals, but the diversity in shot locations and routines, is not to be underestimated.
