Why Clean Sheets Should Not Be A Measure of Goalkeeping Ability

The clean sheet is treated as one of the most important statistics for goalkeepers. Clubs, analysts, and fans use it to rank keepers, decide awards, and discuss legacies. A clean sheet is celebrated with visible gestures: defenders pump fists, managers nod approvingly, and post-match reports highlight the “0” goals conceded. It can often give the impression that the goalkeeper had a perfect game.

The problem is that this statistic is misleading. Clean sheets are the result of a team’s overall defensive performance, not only the goalkeeper’s individual skill. A keeper can make multiple world-class saves and still concede one goal, losing the clean sheet, while another may face only one shot and still record zero.

The clean sheet is an inadequate and often misleading metric for evaluating individual goalkeepers. We need to consider advanced measures that capture shot-stopping ability, decision-making, and proactive defensive contributions, rather than relying on a single binary outcome.

A clean sheet depends largely on the defensive structure in front of the goalkeeper. In elite football, the back four/five, midfield protection, pressing patterns, and team tactics determine the majority of outcomes. The goalkeeper’s individual influence often matters only in high-quality chances. This is why a keeper like David Raya can lead the league in clean sheets while analysts consider Alisson superior: Raya benefits from Arsenal’s structured defense, while Alisson faces more frequent and higher-quality shots behind a less consistent defence.

Similarly, Jan Oblak has three more Zamora trophies than Thibaut Courtois, yet Courtois is widely regarded as the better keeper because he consistently prevents goals in situations that clean sheets alone cannot capture. Joe Hart won more Premier League Golden Gloves than Edwin van der Sar, but this reflects the defensive strength of Hart’s Manchester City teams more than his individual ability.
A clean sheet reduces complex performances to a binary outcome: either 0 goals conceded or not. A 1-0 win counts the same as a 0-0 draw, while conceding once after making fifteen saves is treated the same as conceding multiple times in a rout.

This is however not to suggest clean sheets are solely the product of defence. Elite goalkeepers earn many of them through skill, reflexes, and positioning. The point is proportionality: clean sheets reward strong defensive units far more consistently than individual goalkeeping performance.

A clean sheet gives no information about how much danger a goalkeeper faced. A keeper who makes fifteen saves in a match is treated the same as one who faces three shots, provided neither concedes a goal. Similarly, a goalkeeper who prevents several high-quality chances in a difficult match is not credited beyond the binary “0” outcome.

Shot quality is equally important. Teams that defend well often force opponents into long-range or low-probability attempts, making the goalkeeper’s job easier. Jan Oblak, for example, benefitted from Atlético Madrid’s low block, which reduces the number and quality of shots he faces and while they may not necessarily play like that anymore, it doesn’t change the fact that most of his Zamoras came because the defense in front of him was rock solid. In contrast, Thibaut Courtois often faces high-value attempts behind a more open defensive system and still prevents goals. Clean sheets inflate the apparent performance of keepers in structured defensive systems while underestimating those who prevent high-quality chances. For more context and rather ironically, 2 of Courtois’ 3 Zamoras came at Atletico Madrid, with the only 1 at Madrid coming in 19/20.

A keeper may benefit from missed penalties, shots hitting the post, or defensive interventions before a shot even occurs. Joe Hart’s 4 Golden Gloves(the most in Premier League history by the way) compared to Edwin van der Sar’s 1 illustrate this: Hart’s zeros were supported by Manchester City’s dominant defensive system at the time, while van der Sar performed under far more demanding tactical and positional conditions.

Perhaps the only distinction in the Premier League to this discrepancy is Petr Cech who is widely regarded as the best in Prem history and also has the most golden gloves in history(4 like Joe Hart) but even he had the famous Chelsea defense that only let 15 goals in 38 games.

Expected Goals (xG) measures the likelihood of a shot resulting in a goal based on location, angle, and context. It evaluates the quality of chances but not the keeper’s skill in stopping them. Post-Shot Expected Goals (PSxG) improves on this by considering the trajectory, placement, and speed of the shot after it has been struck. PSxG isolates the goalkeeper’s true shot-stopping ability. For example, a keeper who faces shots totaling 10 PSxG but concedes only 7 goals has saved 3 goals above average. This metric credits keepers for preventing goals they were statistically expected to concede, unlike clean sheets which credit only the team outcome.

Importantly, this does not dismiss clean sheets entirely. Many are genuinely earned through reflex saves, one-on-one interventions, or commanding high claims. However, over a season, the total number of clean sheets reflects the defensive system more than the keeper’s peak performance. PSxG reveals which goalkeepers consistently beat probability and quantify their individual contribution independent of the team. This distinction allows fairer comparisons between keepers like Raya and Alisson, Oblak and Courtois, or Hart and van der Sar.

Modern football demands goalkeepers who contribute beyond traditional shot-stopping. With higher defensive lines and aggressive pressing systems, keepers are both the last line of defence and the first point of attack. Their positioning, decision-making, and ability to intercept danger outside the box directly influence the number and quality of shots the team faces.

Metrics like Defensive Actions Outside the Box measure how often a goalkeeper anticipates through-balls, clears danger, or intercepts attacking threats before a shot is taken. A keeper who consistently executes these actions reduces the likelihood of conceding goals, but the clean sheet metric ignores these contributions entirely.

Passing and distribution have also become essential. Modern keepers frequently initiate attacks, break opposition lines, and maintain possession under pressure. Effective long passes, accurate progressive passes, and quick distribution can turn defence into attack, yet the clean sheet fails to capture these skills. The modern goalkeeper’s value lies not only in saving shots but in preventing them and contributing to team structure, critical actions that traditional statistics systematically overlook.

Goalkeeping is the most context-dependent position in football. Clean sheets, while celebrated, provide an incomplete and often misleading measure of a goalkeeper’s value. They reward defensive organisation more than individual skill and fail to recognise performance under pressure, shot difficulty, or proactive contributions.

To accurately evaluate goalkeepers, analysts, journalists, and fans must consider advanced metrics such as PSxG, Saves Above Average, and DAOTB, which reflect shot-stopping quality, risk reduction, and technical contribution. Clean sheets remain a useful indicator of team performance, but individual excellence requires a deeper look. The best goalkeepers are not always defined by the number of zeros on the scoreboard, but by how many goals they were expected to concede, and how many they prevented through skill, anticipation, and consistent decision-making.