Finding the best goalkeepers in the Eredivisie – data analysis

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The Eredivisie is known for its great youth academies rather than their big-money spending. This shows with the number of young talents they have produced, many of them goalkeepers. The Dutch league has helped numerous keepers further their careers. For example Manchester United legend, Edwin van der Sar, as well as World Cup finalists Maarten Stekelenburg and Sergio Romero. This league is often seen as a stepping stone for players too, the most notable case being Jerzy Dudek. The Polish goalkeeper transferred from Feyenoord to Liverpool, before winning the UEFA Champions League in 2005.

In this data analysis, we will be concentrating on the goalkeepers who have played at least 10 games in the 2019/20 Eredivisie season. Three key aspects of goalkeeping will be used to determine the goalkeeper of the season – shot-stopping, aggressiveness, and passing. In a season that has now been cancelled and where Ajax have not necessarily dominated, these findings are sure to be interesting.

Overview

Although the season has now been cancelled with no winner, 26 rounds had still been played. This means that there is enough data to correctly identify the best and most disappointing goalkeepers so far.

The Eredivisie is more known for its attacking flair, rather than solid defences. Meaning each team’s goalkeepers must be on high alert at all times. When comparing to Europe’s top five leagues, the Dutch league (3.08) falls behind only the German Bundesliga (3.25) in terms of goals scored per match. Meaning that it could be difficult to analyse a goalkeeper’s performance when so many goals are conceded per match.

Finding the best goalkeepers in the Eredivisie – data analysis statistics

Shot-stopping

Using data to analyse a goalkeeper’s ability to save shots can often be misleading. Unlike any position, goalkeeper’s statistics are often reliant on their teammate’s defensive capabilities and his opposition attacking capabilities. For example, a player who faces more shots of higher quality is going to have worse stats than a player who faces the same amount of shots, but of lower quality. Therefore it is important to find the correct data to analyse.

Finding the best goalkeepers in the Eredivisie – data analysis statistics

The graph above shows that the number of shots faced has a direct correlation with the number of goals they concede. Xavier Mous, of PEC Zwolle, faces the most shots per 90 with 7.02 and also concedes the most goals per 90, with 2.29. Meanwhile, on the other end of the graph is Marco Bizot, who has been part of the best defence in the league this season. The AZ keeper faces only 2.75 shots per 90, meaning he concedes much fewer goals per 90, 0.45. Therefore it is important to eliminate the data that reflects a goalkeeper’s defence.

Expected goals are being used more and more in football analysis, and now, even more so with goalkeepers. It takes into consideration the number of shots and the quality of those shots that a goalkeeper faces.

Finding the best goalkeepers in the Eredivisie – data analysis statistics

The above graph shows each goalkeeper’s save percentage against their expectancy to concede per shot they face. The latter stat was calculated by dividing a goalkeeper’s expected goals conceded and total shots faced. Goalkeepers in the top right area of the graph make more saves from harder shots, whereas those in the bottom right area save more from easier shots.

Bizot stands out again here. Although he has been helped massively by his defence this season, this data proves that he still has a safe pair of hands when he is called upon. He has a league-high 83.58% save percentage, however, his expected goals per shot is only 0.24. Bizot has been one of the standout keepers this season, with an incredible 17 clean sheets from 25 games.

Another standout performer in the bottom right area is Lars Unnerstall. The PSV shot-stopper’s expected goals per shot is 0.29, he manages to save 77.59% of his shots.

Looking at the top right area, there is one standout player. Janis Blaswich of Heracles. He has the highest expected goals per shot in the league, with 0.34, however, he manages to save 73.44% of the shots he faces. Heracles success this season has been somewhat of a surprise and a lot of this is down to Blaswich’s shot-stopping ability.

A familiar name for many here is Andre Onan, of Ajax. The 24-year-old has had somewhat of an uncertain season. Maybe having his mind on what elite club he should join in the summer. However, he still proves his worth in this graph. His expected goals per shot are unexpectantly high this season (0.32), but he has still been able to stop 71.62% of shots he has faced.

The next graph is rather similar. It shows us the number of saves each goalkeeper makes per 90 and their saves per goal, meaning how many saves will be made before conceding a goal. This statistic was calculated from doing the sum, number of saves/goals conceded.

Finding the best goalkeepers in the Eredivisie – data analysis statistics

Saves per goal is where we really see Bizot’s dominance this season. He makes more saves than three other goalkeepers (2.34), he also has an incredible 5.18 saves per goal, by far the best in the league.

Some other repeated names in the top left of this graph too, Onana and Blaswich both with above-average saves per goal (>2.26). However, Unnerstall really impresses here. He makes 2.76 saves per 90, and 3.15 saves per goal.

A disappointing player here is Jeroen Zoet. Zoet’s stats may be a little unreliable as he made a mid-season loan move from PSV to Utrecht. Nonetheless, he has struggled this season. He only makes 2.05 saves per 90, and only 1.7 saves before conceding.

This next graph will truly show us how well each goalkeeper has performed regardless of their team’s quality at the back.

Finding the best goalkeepers in the Eredivisie – data analysis statistics

This graph paints a true representation in terms of how effective each keeper is, and how they are performing compared to their expectations. Goals saved above average was calculated by taking their actual goals conceded off their expected goals conceded, giving us a +/- result.

Blaswich is out in front here by some distance, saving 9.57 more goals than was expected. This stat may be down to the surprise of his team’s success this season. With not many predicting their decent form this season.

Two goalkeepers that we haven’t yet mentioned appear in the top three, with similar stats. Warner Hahn has saved 5.87 more goals than he should have, meaning he has had a successful season. The 27-year-old has played 20 games, conceding 27 goals, but managing four clean sheets. Just below him, saving 5.67 more goals than he should have, is Eredivisie veteran Remko Pasveer. The 36-year-old has had a solid season for Vitesse Arnhem, playing in all 26 games and keeping eight clean sheets.

Rounding out the top five is Bizot and Unerstall, saving 4.83 and 3.6 more goals than expected, respectively. Showing their consistency throughout the season.

Aggressiveness

As a goalkeeper, although being aggressive isn’t a necessity, it is extremely helpful to a team’s defence. In this section of the data analysis, we will measure each goalkeeper’s aggressiveness by taking a look at their in-box actions; goalkeeper exits, as well as aerial duels and their success.

Finding the best goalkeepers in the Eredivisie – data analysis statistics

We can see here that most Eredivisie goalkeepers have similar stats regarding aerial duels and exits per 90. The league average is 0.38 for aerial duels and 1.35 exits per 90. Dennis Telgenkamp, of Emmen has the most aerial duels in the league (0.68), with a success rate of 94.74%.

Whether it be rushing out to an attacker to put pressure on him, or relieving the pressure on the defence by claiming a low cross, Alexei Koselev has the most this season, with 2.21. His two-metre height is certainly helpful in these situations, as h­­­e is able to make himself as big as possible, tightening the angle for crosses and shots. He averages a fair amount of aerial duels per 90, with 0.61 and a success rate of 88.24.

Bizot and Blaswich show up here too, above the league average on both fronts. Blaswich with slightly more, 0.5 aerial duels and 1.9 exits per 90 compared to Bizot’s 0.41 aerial duels and 1.72 exits per 90.

A player that stands out here for all the wrong reasons is 1.82m tall Kenneth Vermeer, who has recently transferred to the MLS. He has by far the worst stats, with 0.06 aerial duels and 0.41 exits per 90. As well as conceding 9.59 more goals than expected. These stats may have contributed to his move away.

Finding the best goalkeepers in the Eredivisie – data analysis statistics

Commanding a box is one of the most important abilities a goalkeeper can have. Here we have analysed each goalkeeper’s punches per 90 and claims per 90, as well as their punch/claim ratio. The claim/punch ratio is shown by how big each mark is. The bigger the mark, the more likely the keeper is to claim the ball, rather than punching.

Many modern-day goalkeepers will opt to punch rather than claim, in favour of a safety-first approach. The goalkeepers on the right-hand side opt to punch the ball more often, whereas those on the left are more likely to claim it.

Koselev is the only keeper that isn’t in favour of one or the other. He has a claim/punch ratio of 5.43, 1.35 claims and 0.25 punches per 90.

Joel Drommel uses his 1.93m height to claim most of the crosses he faces, with a ratio of 10, 0.77 claims and only 0.08 punches per 90. A safer pair of hands than most.

Bizot and Timon Wellenreuther both have the most punches per 90, with 0.38. These two are not as safe dealing with a cross, Bizot with a ratio of 1.75 and Wellenreuther, the 24-year-old Willem shot-stopper, with 2.6.

Distribution

A goalkeeper’s distribution almost always mirrors their team’s style of play. For example, Ederson at Manchester City and Marc-Andre ter Stegen at Barcelona. Both teams have possession-based tactics, and their goalkeepers are an integral part of this.

The below graph shows each goalkeeper’s passing data. Passes per 90, average pass length (metres) and their pass accuracy denoted by their marks colour.

Finding the best goalkeepers in the Eredivisie – data analysis statistics

PSV, Utrecht and Ajax all play a mostly possession-based game, opting not to kick it long, rather finding their defenders with simple passes. This is evident in their goalkeeper’s passing stats.

Onana has the highest pass completion percentage in the league, with 88.95%. His average pass length is 29.07m and he averages 19.93 passes per 90. His average pass length is the lowest in the league, suggesting that he prefers to play short balls rather than punt them long. This is also evident in Unnerstall’s passing game, which replicates his team’s. He averages 19.13 passes per game, with a completion of 84.51%.

The goalkeepers in the top left area all tend to punt the ball forward, opting to get the ball upfield as fast as possible. Hence why they all have fairly low pass completions.

Wellenreuther’s average pass length of 41.12m is the highest in the league. With a fairly low success rate of 78.84%. However, with his team, Willem, sitting fifth place, their tactic of punting the ball long is clearly working. However, with others, this tactic is not so successful. For example, Ariel Harush, of Sparta Rotterdam, has been less successful this season. He averages only 15.17 passes per 90, with an average length of 39.52m and success of 72.76%. However, his team sits in 11th.

An interesting player on this graph is RKC Waalwijk goalkeeper, Etienne Vaessen. He averages the most passes per game, with a huge 30. And although his pass length is fairly high with 38.09m he still manages a good pass success of 83.62%. 

Final shortlist

The players listed below are ones that have stood out in more than one category but have not taken the number one jersey in our team of the season.

Blaswich is incredibly unlucky to miss out. The Heracles goalkeeper has been a huge part of his side’s surprise season. He has far exceeded what was expected of him this season. The 29-year-old was expected to concede 43.57 goals, however, he only conceded 34. He has played 26 games this season, conceding 34 goals and keeping seven clean sheets. His punches and claims per 90 exceed the leagues average meaning that he is an aggressive keeper, aiming to help his defence.

A player that has gone under the radar, having played only 14 matches is Unnerstall. The PSV goalkeeper has taken over from Zoet after he left for Utrecht. In them 14 games he has only conceded 13 goals, keeping four clean sheets. He has the third-best goals to game ratio in the league with 0.88 and the second-best save percentage. The German goalie has been integral to PSV’s fourth-place finish.

Last on the shortlist is the familiar name of Andre Onana. Impressive in Ajax’s champions league run last season, and indeed their Europa League campaign this season, it would be rude to leave the Barcelona youth graduate without a special mention. Linked with Chelsea to replace the under-performing Kepa, he is likely to move on in the summer. This transfer speculation may have impacted his fairly average season.

Conclusion 

17 clean sheets, 0.45 goals per 90 and 11 goals conceded in 24 games. These stats can’t be ignored, and that’s why Marco Bizot has been the best goalkeeper in the 2019/20 Eredivisie season. An incredible season for the 29-year-old which came to a close much too soon. The Dutchman, albeit with the help of his defence, kept a clean sheet in just over 70% of his games. AZ Alkmaar’s keeper tops the majority of statistics in the shot-stopping section with an impressive 5.18 saves per goal, whilst stopping almost five more goals than he was expected to. He has above the league average in exits and punches, showing that he often helps out his defence and puts the opposition under pressure.

This data analysis has proven that apart from the top teams in the Eredivisie, defences are not that strong. Therefore an above-average goalkeeper is required to succeed. Focusing on three key aspects has allowed us to find the best goalkeepers in each area, and find those who dominated in all three, such as Bizot. There are many top keepers currently in the Eredivisie, some with great defences and some without. But what’s for sure is that this league will continue to develop and nurture goalkeepers for Europe’s elite.