How Alisson Saved Liverpool’s Season

Liverpool really did that. After an absurd run of losses in the middle of the year, and sitting in eighth place with ten games to go, the Reds went on to win eight, draw two — a 99 point pace for more than a quarter of a season — and finish third in the league, securing Champions League football for the fifth year running.

Among the many heroes who will receive acclaim for this feat — Trent for his creativity, Fabinho for bringing stability, Thiago for running the midfield, Bobby and Sadio for finally finding their shooting boots, Nat and Rhys for somehow keeping their head above water in the Premier League — Alisson Becker is probably the one people will remember most clearly, specifically for his injury time winner — the first headed goal by a goalkeeper in the Premier League and the first ever goal by a Liverpool goalkeeper, period — against Sad Sam Allardyce’s West Bromwich on May 16th.

(Because Leicester are undefeated champions when it comes to choking on the final day of the season, Alisson’s goal — disregarding all the intangible psychological effects it must have had on the squad — didn’t actually, mathematically matter much. A draw against WBA would’ve still seen the Reds finish on 67 points and in the top four. This is a silly semantics point for nerds I will never mention again.)

However, significantly less heralded have been Alisson’s contributions at the other end of the pitch. The Brazilian was absolutely scorching hot between the sticks to finish out the year, and I’m going to make the case he made a much bigger difference for the Reds in the more traditional goalkeeping sense than with climactic last-gasp headers.

While the 2020-21 season had many peaks and valleys, for the purposes of this article, we will be separating the Reds’ final, incredible ten-game run from the rest of the year.

Over the course of the season, Liverpool conceded 45.4 expected goals against, or an average of 1.2 xGA per match. In the ten-game run, they conceded 10.7, or 1.07 xGA per match. This 10% improvement can have been caused by a combination of factors; the quality of the opposition, the added defensive screening work of Fabinho in midfield, or the improved performances of Nat Phillips and Rhys Williams, among other things.

However, from those 10.7 expected goals conceded, Alisson allowed only 6. That is a difference of 4.7 goals in ten matches, an overperformance of 44%. Extrapolated into a full season, that would mean a difference of 18 goals, or the entire goals tally of Bruno Fernandes. It is spectacular goalkeeping.

Could it be that the opposition in these matches simply missed the target? Well, Alisson saved 32 of 38 shots, 84%, while the highest save percentage in the Premier League this season was 76.8. Previous to this run of games, Alisson’s save rate in 2020-21 was a mere 68.5%. In other words, he had plenty of work to do.

Well, maybe the shots were just straight at him and easy saves. To look at this, we consult the post-shot expected goals. For those of our readers who are unfamiliar with this metric — aka people who are much, much cooler than me — it measures the likelihood of a goalkeeper saving a given shot on target, based on a number of factors such as distance to goal, placement, etc.

The PSxG value of the shots Alisson faced in the final run of games was 10.3, meaning that even by this standard, the Brazilian conceded 42% fewer goals than would be expected. A rate of 0.43 goals fewer than expected per 90 minutes is more than twice as high as the best in the league — Emi Martinez’s 0.2 — and a huge — six-fold in, fact — improvement on the 0.07 rate Alisson himself had produced previously in the season.

To sum up, in a ten game run where the Reds drew twice and won two games by a single goal — starting only two weeks after the loss of his father — Alisson found the form of his live and saved over 4 goals more than expected, rescuing Liverpool’s Champions League hopes long before he rose to divert a perfect header into the far corner at the Hawthorns.

He should be commended for going so comprehensively above and beyond his job description and it is a moment I will never, ever forget, but the fact that he is also one of the best in the world at the thing he is supposed to be doing shouldn’t get lost in the mix either.