Revealed! The best goalkeepers in the Premier League this season – with unique data
Is he a Kepa?
We probably didn’t surprise you with news that Alisson would outperform Kepa and other Premier League newcomers when measured against the same sample of shots. But we might spark a debate with some of the other findings.
As above, Kepa is a top-third keeper in the Premier League – but when compared to some of the division’s other newcomers, he’s not differentiating himself as much as his price tag would suggest. Vicente Guaita, who joined Crystal Palace from Getafe on a free transfer, is a top-five keeper when given the same shot sample opportunity as all other top-flight keepers. Bernd Leno and Rui Patricio – comparatively inexpensive options for Arsenal and Wolves – aren’t far behind.
All fascinating stuff, but what if we need to see one keeper’s strengths compared to another’s? In the following visual, we’re aggregating all shots faced by both keepers and showing which on-target areas each keeper displays strengths over the other:
Alisson, we can see, would concede seven fewer goals than Kepa in this shot sample. He’d do so because he’s a comparatively exceptional keeper facing low, centre and right-of-centre chances. Kepa, meanwhile, is better going to his left, though with far less contrast.
Guaita vs Kepa in Spain
This is information Chelsea would be receiving in hindsight, but we can also go back to the 2017/18 season and see how Kepa compared in La Liga. Guaita was also there then, so we’ll bring him in too.
Kepa conceded 43 goals in 30 matches while making 96 saves for an Athletic Bilbao side that finished fifth-bottom. Guaita conceded 26 goals in 34 matches while making 85 saves for a defensive-minded Getafe side that conceded fewer goals than Champions League holders Real Madrid and Champions League qualifiers Valencia. It seems like a transfer that Palace deserve more credit for than they’ve received.
But how do the two keepers rank using embeddings to measure against a uniform shot sample? It favours the expert’s eye test over the basic team data outlined above: Kepa was better than Guaita, but not substantially. The 24-year-old ranked seventh in the division at 0.10 xG prevented per 90, while Guaita was eighth at 0.097. For the sake of comparison with our gold standard, Alisson was second in Serie A at 0.33 xG prevented per 90, behind Samir Handanovic.
It’s even more interesting when we consider Kepa and Guaita directly against each other in 2017/18:
Kepa (now red) still displays superiority going wide left when compared to Guaita, but he’s also mimicking some of the strengths Alisson held over him (low and right of centre).
Here and now
If we zoom back out to the larger context of the 2018/19 Premier League, we’ll break this down matchday by matchday to see how these first-year EPL keepers have evolved over the season in comparison with three others:
NOW READ THIS...
Alisson was the best keeper in the Premier League through to Matchday 21, and David de Gea has held that title since. Kepa has been above average all season but not exceptional.
Leno had to earn his position and didn’t play particularly well when he took over from Petr Cech, but he’s steadily improved. Rui Patricio has also been above average in his first season but peaked early.
It’s no secret that world-record signings don’t necessarily mean world-class performances. But a smarter way to make data-driven recruitment decisions has arrived.
Interested in seeing additional leagues? Find expanded work with the STATS AI Goalkeeper Index here. Interested in finding out more about STATS’ method? Read Paul Power’s Trading Places – Simulating Goalkeeper Performance using Spatial & Body-Pose Data on the STATS AI page. Stay tuned for our forthcoming striker simulations.
Follow STATS Football @STATSonthePitch