Stats Study: Why Alisson and Oblak are pipped to pole in top goalkeeper ratings
Having entered a new transfer window, it’s fair to say that goalkeepers took centre stage in the previous one, with three of the most expensive fees over the summer spent on the last line of defence.
Alisson’s arrival at Liverpool broke the record for a shot stopper, only for Chelsea to smash that benchmark later in the window following the sale of Thibaut Courtois to Real Madrid, with Kepa Arrizabalaga signed as the Belgian’s replacement.
With goalkeepers finally seeming to catch up in terms of their valuation in the modern game, signalling a realisation in the importance of a top class number one, we’re taking a deep dive into the top performers in that position so far this season.
This study is an attempt take a more in-depth look into what statistics mark out a top quality goalkeeper, using the average figures of the 79 keepers in Europe’s top five leagues to have played 15 or more league games in 2018/19.
The base criteria for this assessment is save success rate (the percentage of shots on target faced that a keeper saves) to bring about the top nine players in that regard, and it’s encouraging news for Liverpool.
The fee spent to secure Alisson’s services from Roma certainly raised eyebrows in the summer, but the Brazilian has lived up to that price tag to now without question. He boasts the best save success rate in Europe’s top five leagues (84.2 per cent) having also conceded the fewest goals per game (0.47).
However, while both statistics are very important, they don’t tell the whole story of just how well a goalkeeper is performing, at least based on expectations of said player. Liverpool, sitting pretty at the top of the Premier League, have unsurprisingly faced considerably fewer shots than most, and as such Alisson is called into action less frequently.
It’s also no surprise, then, that the 26-year-old is some way down on the average (3.06) in terms of saves per game, with a modest 2.29. A keeper can only save the shots they face, of course, but a significantly busier number one has a lower chance of saving such a high proportion based on both the volume of shots faced and quality of said chances.
The latter is something we’ve assessed here using Opta’s ‘big chance’ statistics, looking at each keepers' save success from such situations, though Alisson again performs extremely well. The Brazil international has saved nine of the 14 big chances that opponents have had on target this season, conceding the other five, garnering a save success rate of 64.3 per cent.
There is, however, one keeper that can beat that figure, with Getafe’s David Soria - ninth in terms of overall success rate - saving a whopping 13 of 18 big chances faced on his goal. The 25-year-old’s heroics have ensured that his side have conceded fewer goals than the likes of Barcelona, Real Madrid and Sevilla, and only fewer than Atletico Madrid in La Liga.
Los Colchoneros number one Jan Oblak is unsurprisingly among the top nine keepers for save success too - in third - and he also scores well above the average (42.65 per cent) when it comes to big chance save success, with 52.6 per cent. Again, unsurprisingly the Slovenian is below the average when it comes to saves per game (2.5) though, along with Soria (2.72).
So who are those oft-tested goalkeepers that still manage to maintain exceptional save success rates?
Girona’s Yassine Bounou certainly stands out from the crowd in that regard, boasting the eighth best saves success in all of Europe despite producing the second most saves per game (4.56). The Moroccan has been in sparkling form at times, but while he concedes below the average number of goals per game, the 27-year-old perhaps isn’t quite the most impressive performer across the board in our study.
There is one category developed that we haven’t touched upon after all, and that is a closer look into clean sheet figures that we have labelled 'clean sheet quality'. The keepers equivalent of a goal in many ways, it’s a raw statistic that requires elaboration to really understand how influential the man between the posts was in securing it.
After all, one can keep a clean sheet without having to make a single save. In fact, RB Leipzig stopper Peter Gulacsi - who also ranks in our top nine here - has kept four clean sheets in such circumstances this season of seven in total. We, instead, have looked at the number of saves per game keepers have produced in the matches in which they have kept clean sheets to get a better grasp of just how impressive their overall tally may be.
For example, it’s that man Alisson again that leads the way in terms of overall clean sheets (12) this season, but in said matches he has procured a modest 2.17 saves per game, which is down on the average of 2.78. In this category it is Fernando Pacheco that really stands out from our study, averaging a massive five saves per game in the six matches in which he has kept a clean sheet. Overall, then, the Deportivo Alaves keeper has made four more saves on route to six clean sheets (30) than Alisson (26) has made in 12, with the Spaniard playing a decisive role in his club’s remarkable season so far.
Elsewhere in Spain, Sevilla’s Tomas Vaclik is one of three players assessed in detail here that ranks above the average figure for the four categories analysed in the above chart, with the aforementioned Bounou another. Inter’s Samir Handanovic isn’t too far off, but it’s Nice’s Walter Benitez that is arguably the most impressive performer of the lot.
The 25-year-old Argentine ranks second to Alisson in terms of overall save success (81.5 per cent) in qualifying for this study, and places among the top four in all four categories assessed thereafter. The South American is fourth for saves per game of the nine players here, well above the average in Europe with 3.53, and in the same position when it comes to the percentage of big chances he has saved (61.9).
Benitez places third for goals conceded per game (0.73) behind only Alisson and Oblak (0.72), again far superior to the average in that regard (1.32), and second to Pacheco in terms of the volume of saves produced in keeping a clean sheet (4.86 per game).
For those reasons and more it’s he that has earned the highest WhoScored.com rating of any goalkeeper this season (7.19), and while Liverpool’s new star between the sticks has undoubtedly been a huge success, if there is one shot stopper in Europe that arguably deserves more credit it’s the Nice guy in goal for Patrick Vieira's side.
