Thanks for sharing, that's really interesting and I'm curious to read more.
But I'm looking at this and I'm seeing some very simple descriptive statistics displayed in a smart fashion, but not exactly what I'd call advanced stats? I mean, % of clean sheets is hardly even a measure of goalkeeper performance but more of the team as a whole. I guess the ones that might be more advanced are the likes of Shot Diff and Distribution Quality so I'd definitely be curious to understand those.
I'm not convinced by your argument that Karius is "better" in "every other aspect" though. You cast doubts over Oblak's shot stopping abilities by hinting that those may not be "him" but "the system he plays", however you don't seem to apply the same logic to Karius. If you're asked to play with a higher line and come to collect/punch the ball or clear the line in more advanced positions, then you're bound to have higher numbers in those - and a higher success rate - than if you're not generally asked to do so, but may only come forward when your system has failed and you have to come up in riskier situations as a last resort.
Stuff like counting the number of punches and then dividing it by 90 minutes is hardly advanced statistics, and it seems to me to be *much* more reflective of a team's tactics than a consistent overperformance in shot stopping ability as displayed by the likes of Jan Oblak and De Gea. I don't particularly see any reason why it is assumed that a goalkeeper can't adapt to playing in a more proactive system, and to me there seems to be a whole overestimation of the different styles of play when it suits the argument. Goalkeepers have evolved drastically in the past few decades but their scope of play is still the most limited of all football positions.
As for Klopp's previous choices, I have no idea who was his goalkeeper in Mainz, but I have never particularly looked at Weidenfeller as a proactive sweeper keeper, and it did take him over 2 years to send Mignolet to the bench. So I don't know what that says about his preferences to be honest (unless Weidenfeller was in fact a different player than I seem to recall). If rumours are to be believed anyway, he's actually looking for someone better than Karius...
A lot of statistics, no matter for which position, are down to how a team plays and tactics in general. Salah's stats for us are amazing and of course down to individual quality, but also down to the way we set up as a team and play to his strenghts. Same for some of Karius' statistics and Oblak's, both teams play a certain style of football that favours their goalkeepers qualities. Fully agree with that. People on here were comparing goalkeepers solely based on save%, so I'd say these charts are more 'advanced' than just counting the amount of shots a goalkeeper saves. Right now this is the best we have at comparing goalkeepers (on the basis of statistics), I think.
The advanced ones are shot difficulty, which, if I recall correctly, was partly measured by the xG (expected goals) statistic which takes into account the position of the shot, angle of the shot, how hard it was hit, where it ends up etc. Another important one is the aggression% (how often does a goalkeeper come out for high balls, intercepts through balls etc,...) and the parried safe%. As you can see, due to the system Atletico plays, Oblak is a very passive goalkeeper. Not saying he can't be pro-active, but all he really has to do is save shots (which he does at world class level, of course).
Contrary to popular belief, Karius parries shots to safe areas more often than the average goalkeeper. People only remember the times he didn't (Dezko's goal for example).
Not saying goalkeepers wouldn't be able to adapt. Take Mignolet for example, his save% at Sunderland was 76%, that's Pope / De Gea numbers this season. At Liverpool that drops to 59%. Mignolet didn't become a worse shot stopper, he just was exposed by the way we set up, he's not a sweeper keeper and he just couldn't adapt. I'm not saying Oblak for example wouldn't be able to adapt, but odds are that he can't. At Atletico he apparently (according to the xG stats / shot difficulty stats) faced the easiest shots difficulty in Europe playing behind their defensive unit with half the shots he faced coming from outside the box. Of course his save% is very, very high.
I'm not against getting a new goalkeeper to compete with Karius, just trying to show to people that he isn't nearly as bad or average, when compared to other goalkeepers, as people make him out to be.
Oh to have those save % and catches.
As explained in the paragraph above, Oblak gets to pad his numbers because half the shots he faces are from outside the box. Karius only faces 30% of his shots from outside the box. Also compare the shot difficulty difference, Karius faces far more difficult shots than Oblak does.
With regards to the catches, you have to look at the aggression% (I think), Oblak rarely comes out to catch a ball, according to the numbers only 5-6% of the time, compared to Karius' 15% (again, it depends on the system their team plays). Oblak tries to catch far less, so the odds of him failing to do so or having to punch, are far lower than for Karius. Oblak only comes when he is 100% sure and the defence in front of him, in general, just requires him to come for far less crosses than Karius. His number of catches will likely still be higher than Karius 'if he would come more often, just down to how tall he is and his reach etc, but both his save% and catches would drop considerably when playing for a team like us, City, Barcelona etc.
Just to make sure, these are not my observations and I didn't come up with the numbers, I do agree with them though.
