GOALKEEPER PERFORMANCE IN THE 21/22 PREMIER LEAGUE SEASON

Goalkeeper Performance in 2021/22 Premier League Season


With the end of the 21/22 premier league season, the awards have been given out with Son and Salah sharing the Golden Boot and Ederson and Alisson sharing the Golden Boot. Ederson has now won the award 3 years in a row, however, does this mean that he has been the best Goalkeeper in the last 3 years? Most people would disagree. Man City's defence conceded only 0.83 xG/match while Liverpool's conceded 1.03xG/match meaning that a lot of the clean sheets Ederson were influenced heavily by the defence and less on himself. But this begs the question, What Can we Use to Judge the Ability of a Goalkeeper.

This is where PSxG comes in. Post-Shot Expected Goals(PSxG) is a metric to measure the likelihood of a shot going in after it has been taken. It measures the quality of the shots a team is allowing. The difference between this and xG is that xG is a pre-shot metric while PSxG is a post-shot metric. xG measures the quality of a given chance while PSxG measure the quality of the actual shot. So for goalkeepers the PSxG-Goals Allowed shows how many goals the goalkeeper is preventing. This metric helps to account for the fact that not all teams have good defences and thus conceded high number of chances and high quality chances. We all remember De gea's infamous 17/18 Premier League season. His PSxG-Goals Allowed per 90 was 0.17 which means he was preventing 0.17 goals per 90(FBREF). Most Goalkeepers hover around -0.02 as the average. This puts into perspective how good of a shot stopper he was that season.

The next Metric is OPA which measure the amount of defensive actions Outside the Penalty Area that a goalkeeper does. This shows how often they contribute other to the actual game besides shot stopping and measure their sweeping ability





The graph above shows the performance of every PL starting goalkeeper in the 21/22 season. Ederson was 13th in PSxG-GA/90 yet he won the Golden Glove. Pope leads in OPA/90 but due to Burnley's "Route One" style of play it's somewhat expected. A surprise here is Jose Sa who prevented 0.25 Goals /90 which is an astronomical amount. The Golden Glove would have to go to him in my opinion. However, such a high performance in that category is rarely maintained over 2 seasons but Sa should still remain a quality shot stopper. Then there's Alisson who is probably the best Goalkeeper in the Premier League and has been for a while as he is the perfect blend between Sweeping and Shot Stopping. Truly a gem.

In conclusion, The Golden Glove award is should use a different metric or its definition should be changed. We should us PSxG , OPA, Crosses claimed and Launched Pass % (To be discussed later) to judge a goalkeepers abilty.



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