When he joined Atletico Madrid in the close season of 2014, Jan Oblak became the most expensive goalkeeper in Spanish top-flight history at €16million.

Signed on a six-year deal, the fact that he struggled to dislodge Atletico number one Miguel Angel Moya for the first seven months of his time at the club did not seem too concerning for Oblak, as he was still only 21 and had only managed 60 top-flight appearances in four seasons in Portugal across various loan deals and with his parent club Benfica.

He finally made his LaLiga debut on March 21, 2015, at home to Getafe and has missed just 10 league matches since then for Atleti. On Saturday, he is due to make his 200th appearance in Spain's top flight when Atleti visit Valencia.

Since his debut, Oblak has consistently posted goalkeeping numbers that are world class. Across the top five European Leagues since his debut date in March 2015, the shot-stopper has recorded 36 more clean sheets than any other goalkeeper (111), ahead of fellow Slovenian Samir Handanovic. Looking at the 100 goalkeepers to have played at least 7000 minutes across the top five European leagues in this period, he is the only one that has kept a clean sheet in more than 50 per cent of his appearances (56 per cent) and also has the best minutes per goal conceded ratio of all 100 keepers (145 minutes per goal conceded).

It could be argued that being the goalkeeper of Atletico Madrid; who are notoriously defence-minded under the stewardship of Diego Simeone, Oblak's numbers could be skewed by a highly protective defensive unit in front of him, but the numbers suggest otherwise.

Looking at the Expected Goals on Target metric (xGoT), we are able to analyse the quality of the shots that goalkeepers face on target, based on a wealth of historical shot data.

This is an extension of the standard Expected Goals model, as it factors in shot placement in addition to the usual variables such as assist type, shot angle, distance from goal and whether the shot was headed. By using xGoT we can isolate the goalkeepers' performances independently of the quality of the defence in front of them.

Oblak has faced an xGoT total of 167.8 over his 199 LaLiga games, which equates to an average of 0.85 per 90. In layman's terms this means that the 'average' goalkeeper would be expected to concede 168 goals from the shots in these 199 appearances.

As previously stated, we know that he is a well-protected goalkeeper based on watching Atletico play and the numbers back this up. Of the 100 goalkeepers to have played 7000 minutes of top five European league action since the Slovenian's debut, only four have faced a lower xGoT per 90 on average.However, when comparing these averages to number of goals he really concedes, we can see how phenomenal Oblak is.

Goals Prevented is a metric that can be generated from taking an xGoT total away from the number of goals a goalkeeper really concedes (excluding own goals, as they have no xG value).

When comparing the nine of our 100-goalkeeper list to have faced an average xGoT per 90 of less than one, and displaying their average goals prevented per 90 alongside it, only one keeper stands out.With an average of 0.26 goals prevented per 90 minutes since his debut, Oblak is the best of the 100 goalkeepers to have played 7000 minutes in this timeframe and stands out amongst his peers. His number suggests that on average, he is saving a goal every four games with his saves for Atletico.

If you look at the overall Goals Prevented numbers compared to the 100 goalkeepers under consideration since March 2015, Oblak stands out even further.In 199 league appearances for the Madrid side, Oblak has prevented 52 goals with his saves. This is 18 more than the next best goalkeeper, Hugo Lloris (34).

Excluding own goals, Oblak has conceded 123 goals in his 199 LaLiga games, when based on the quality of shots on target that he has faced, you would expect the 'average' goalkeeper to have conceded 168.

The metric 'Goals Prevented Rate' can account for different goalkeepers facing a different number of shots through a period of time. An example of this is that Thibaut Courtois and Ederson have the same Goals Prevented Rate of 1.05 in this timespan, despite the former facing more and higher quality shots. Normalising for the volume of shots allows us to see that both goalkeepers were expected to concede 1.05 goals for every goal that they actually conceded.Oblak's Goals Prevented Rate during his LaLiga career is 1.45. This is way above any other goalkeeper since March 2015. For every goal that Oblak has conceded for Atletico, he would have been expected to concede 1.45.

From looking at the numbers that Oblak has posted in his La Liga career so far, it is clear to see that he is a genuinely world-class goalkeeper and at 27, he still has many years left at the top level.