Goalkeeper data analysis: WSL 22/23

Goalkeeper analysis is incredibly difficult. I know, football analysis in general is quite complex, but for goalkeeper analysis, you need a particular set of skills to do it adequately.

In this article, I’m going to look more closely at what goalkeeper analysis entails, what goalkeeper roles there are and looking at which goalkeepers performed the best in WSL 2022–2023.

Contents

1. Theory of goalkeeping analysis
2. Goalkeeper roles: Shot-stopper
3. Goalkeeper roles: Sweeper keeper/ball-playing
4. Importance of team tactics
5. Data
6. Shot-stopping
7. Distribution
8. Claiming
9. Defensive actions
10. Final thoughts

Theory of goalkeeping analysis

I know I’ve said it before, but there are three important reasons why goalkeeper analysis is more complex than regular player analysis. The first is that you need more technical knowledge of how to judge goalkeepers’ abilities. It means that you need to know about how to make saves, what kind of decisions of techniques you have to make and how you need to close down different angles. These are just a few examples, but you need to know a lot more about how to use your body and how it reacts, than you do with regular player analysis.

The second one is that data analysis is more complex because there are just fewer metrics you can use to make it representative. We have some good data for shot-stopping, but other areas as claiming, sweeping and distribution are quite limited — especially since goalkeepers’ actions are always related to defenders and never in isolation.

Complex GK Union: Unveiling the unresolved aspects of shot-stopping data in Football

The third one is the fact that you need to have a relatively good command and understanding of the tactics of a team. Goalkeepers are very important in preventing goals, but are more and more included in possession of the ball. Build-ups quite often start with goalkeepers.

Goalkeeper roles: Shot-stopper

The first role that we look at is the shot-stopper goalkeeper role. This role focuses on saves, reflexes and parries. These goalkeepers are known for their agility, reflexes, and quick reactions when facing shots from opposing players. Shot-stoppers are often characterised by their capacity to make spectacular saves, diving to reach shots in the corners of the goal, parrying powerful strikes, or using their hands or feet to deny scoring opportunities.

In the table above you can see the goalkeepers that fit that the shot-stopping roles the best. This means that these goalkeepers score very high on the profile of shot-stopping goalkeeper, but this doesn’t mean they perform the best. It is an indication of their playing style.

The top 3 goalkeepers in this profile are Zinsberger (Arsenal), Earps (Manchester United) and Ramsey (Everton).

Goalkeeper roles: Ball-player

These goalkeepers are highly skilled at using both their feet and their hands to maintain possession and initiate attacks from the back. They are comfortable receiving back passes from defenders, controlling the ball under pressure, and making accurate and precise passes to teammates across various distances on the field. Ball-playing goalkeepers are also proficient at playing long balls and delivering pinpoint goal kicks or throws that can launch counter-attacks or bypass opposing players.

In the table above you can see the goalkeepers that fit that the shot-stopping roles the best. This means that these goalkeepers score very high on the profile of shot-stopping goalkeeper, but this doesn’t mean they perform the best. It is an indication of their playing style.

What’s interesting is that the top three goalkeepers for this role is 66,6% the same with Zinsberger and Earps, only D’Angelo comes into the top three. This indicates that D’Angelo is more of a specialist goalkeeper and Zinsberger and Earps are more allround.

Importance of team tactics

Goalkeepers are pivotal to team tactics in football, as they play a multifaceted role that significantly influences the outcome of a match. Their importance lies in their ability to both protect the team’s goal and act as an essential component of the team’s tactics.

Goalkeepers are the last line of defence, responsible for preventing the opposing team from scoring goals. Their shot-stopping abilities are crucial in preserving a team’s lead or keeping the score level. A skilled goalkeeper can single-handedly deny opponents’ scoring opportunities with reflex saves, positioning, and anticipation.

Goalkeepers are often seen as the on-field generals, directing and organising the defensive line. They play a vital role in coordinating the team’s defensive shape, ensuring players maintain proper positioning, and communicating important information about opponents’ movements. This role is essential for maintaining a solid defence.

In modern football, goalkeepers are expected to be proficient in distributing the ball accurately. They initiate attacks by delivering precise passes to teammates, enabling the team to build play from the back. Goalkeepers who can distribute effectively help in maintaining possession and breaking through opponents’ defensive lines.

However, goalkeepers also face challenges due to defensive tactics employed by opposing teams:

1. High Pressing: Teams often employ high-pressing tactics to disrupt the opponent’s build-up play. In such scenarios, goalkeepers may face intense pressure when attempting to play short passes or distribute the ball. Any mistake can lead to transitions and counter-attacks.
2. Set Pieces: Defensive tactics in football often involve conceding fewer open-play chances and relying on set pieces for offensive opportunities. Goalkeepers must remain alert during corners and free-kicks, as they are susceptible to conceding goals when facing well-executed set pieces.

Data

Data is super important in terms of analysis and if we are doing data analysis it’s important to know that data isn’t 100% fallible. In women’s football not all leagues are covered equally and not all data is 100% correct or complete. In that light, we need to understand how difficult it is to make assumptions and conclusions from that data.

The data I’m using for this next part comes from Opta and the tables above from Wyscout. For the Wyscout data and for the profiles, I don’t look as much for minimal minutes, but with the Opta for the next analysis, I’m more concerned with the minimal amount of minutes.

The data only concerns the 2022–2023 season because that’s a full season and that gives us the best idea of how well or badly a player has performed.

Data analysis: Shot-stopping

So what is shot-stopping? It’s basically every metric in data that concern the oppositions shots, expected value, saves and expected saves value of goalkeeper.

In the scatterplot above you can the number of shots vs the save rate in %. This gives us an idea of not only the save rate, but also the save rate in relation to the quantity of shots conceded — which is important to create a distinction between good and poor teams.

What we can see is that Mary Earps, Janina Leitzig, Tinja-Riika Korpela and Mackenzie Arnold not only are among the highest save rate % for players with at least 300 minutes, but it’s also linked to the actual shots on target against — which makes them overall the best in responding to shots.

The next step is to evaluate whether a goalkeeper isn’t only producing quantity saves, but also is she underperforming or overperforming with the shot-stopping. In other words; is she conceding more or fewer goals than expected?

In the table above you can see the goalkeeper who perform best in PsxG +/- — but what does that mean? It is the Post-shot expected goals minus the conceded goals. So the expected goals to concede, from the moment the shot is taken, minus the actual conceded goals. The player with a positive number are the players that are overperforming.

Here we can see that Emily Ramsey, Ann-Katrin Berger and Janina Leitzig come up on top in case of overperforming the expected values in shot-stopping.

Data analysis: Distribution

In the table above you can see which goalkeeper has the highest average length per pass.

This metric can give us a few things, it indicates which goalkeeper might pass the ball short and might pass the ball long. It also gives us an idea of team tactics and which role that particular goalkeeper has.

Data analysis: Claiming

In the table above you the top 10 performers for crosses stopped in percentages. What does it tell us?

It tells us which player has the highest percentage of stopping/claiming crosses — and therefore is active in leaving the line and claiming the ball, rather than waiting and letting the defenders deal with it all the time.

Data analysis: Sweeping

A goalkeeper not only needs to be able to adequately react in her own box, but also a modern goalkeeper needs to be good outside of the penalty area. In other words, a ball-playing goalkeeper is also asked to keep a high line and interact in defensive actions.

If you play higher up the field, it’s evident that your defenders will play high too — which means that the goalkeeper needs to be more progressive on the pitch and do the sweeping actions.

Final thoughts

The aim of this article was to look at data what we can do with it to evaluate goalkeepers. With data we can see what role is best fitting for a goalkeeper: ball-playing or shot-stopping.

But we can also see where goalkeepers are good at, what their intention is and what playing style they have. It gives us more information about how a goalkeeper can be used best and that there are different types of goalkeepers.

But my main point was to show that with data you can look at more things than only shot-stopping. Of course, shot-stopping is very important, but it’s not the only way of evaluating a goalkeeper, nor is it the only thing a goalkeeper can do.