How can we evaluate Shot Stopping?๐งค
Last week, Remko Pasveer announced his return to Heracles Almelo. Trying to save his former club from relegation might be his final challenge before potentially retiring after this season.
Coincidentally, a few days later I came across his incredible 21/22 season at Ajax while working on my player evaluation research. The aim of this project is simple: turning raw Wyscout data into clear, interpretable football attributes.
When it comes to goalkeepers, the most sophisticated way to evaluate shot stopping is by comparing goals conceded to ๐ฝ๐ผ๐๐-๐๐ต๐ผ๐ ๐
๐ (PSxG). Converting this into a percentage of PSxG prevented shows that Pasveerโs 21/22 season was ๐ฃ๐บ ๐ง๐ข๐ณ the best shot-stopping performance of any Eredivisie goalkeeper since 18/19.
His ๐๐ผ๐ฎ๐น ๐ฃ๐ฟ๐ฒ๐๐ฒ๐ป๐๐ถ๐ผ๐ป % was at least twice as high as every other goalkeeper's, except for Marco Bizot in 19/20. During that season, Bizotโs market value increased by over 50%. The former AZ keeper is now the back-up to a former Golden Glove winner at Aston Villa. That year, Bizot also led the second metric on my scatter plot: ๐๐น๐ฒ๐ฎ๐ป ๐ฆ๐ต๐ฒ๐ฒ๐๐ ๐๐ฑ๐ฑ๐ฒ๐ฑ.
Not every goal is worth the same. A crucial 90th-minute save to preserve a clean sheet can be worth up to 2 points; the difference between relegation and survival, or silverware and disappointment.
Using a Poisson Distribution, I estimated how many additional clean sheets goalkeepers kept ๐ข๐ฃ๐ฐ๐ท๐ฆ or ๐ฃ๐ฆ๐ญ๐ฐ๐ธ expectations, per 90 minutes.
The only other goalkeeper outperforming Pasveer in this metric is ๐๐ผ๐ฒ๐น ๐๐ฟ๐ผ๐บ๐บ๐ฒ๐น this season. With a market value of just โฌ2.0M, a move for the 29-year-old might be worth a shot.