Thursday, December 29, 2011
Is Szczesny Overrated? A Statistical Analysis.
Let's face it - we all love SZCZ. Since Jens was dropped in 2007 (in my opinion ill-advisedly) we've had to put up with some of the less convincing goalkeepers in Arsenal's history, namely Almunia, Fabianski and Mannone. Each, for a brief period, looked like they might have the necessary chops, but all have also had a series of goalkeeping calamities during their period at the club. The permanently terrified look on Almunia's face still haunts me.
So when SZCZ turned up it was a relief for a number of reasons. One - he was confident. Goalkeepers HAVE to be confident. They play in the most unforgiving position on the team and they can't beat themselves up every time they concede a goal, or mess-up a goal kick. Secondly - he looked the real deal. He made big saves in big games (Udinese away anyone?) and he could spread himself, Schmeichel-style, in one-on-one situations. In short, he looks dominant and confident, and that has helped our general defensive improvement since September.
But, while perusing Twitter yesterday, I saw some interesting stats posed by Orbinho on Twitter relating to Arsenal and Spurs this season in the league. Both teams have scored the same amount of goals (34) and Arsenal actually have a higher shot-to-goal ratio than Spurs. (15.1% vs. 14.5%). We also have a similar passing accuracy rate. So Spurs are not actually any better going forward than we have been this season.
Where the stats get even more interesing is in defence. We have conceded 26 goals in total compared to Spurs 19. Yet, we have allowed fewer shots on goal (68 to 95). This means that SZCZ's has only saved 61% of the shots on goal that Arsenal have allowed, while Friedel has saved 79%. Moreover, in a statistic entitled 'errors for goals' (committed by any member of the team), Arsenal have committed 7 errors while Spurs has committed 0.
The conclusion would therefore appear to be clear. As Orbinho put it:
"Effectively the difference between Arsenal & Spurs is that Brad Friedel is far outperforming Szczesny and individual errors by defenders."
Now stats are obviously problematic. The main point of Michael Lewis's Moneyball is that looking at the wrong stats can lead to disaster in sports. And Arsenal's defensive stats have been horribly skewed by the 8-2 drubbing in August.
But, there are some things which I don't think can be escaped here. Namely - Friedel is considerably more likely to make a save than SZCZ when there is a shot on goal. Yes, not all shots are alike, but the twenty percent difference in shot-stoppage % between the two keepers is considerable. And these saves are from both inside and outside the box:
Friedel v Szczesny Inside box Goals conceded 17-20 Saves 34-25 Save % 67%-56% - Outside box Conceded 2-6 Saves 37-15 Save % 95%-71%
Or to put it even more bluntly, for every five shots on goal each keeper has faced, Friedel has conceded one, while SZCZ has conceded two. SZCZ looks particularly weak from outside the box.
So, is SZCZ overrated? I would still argue no, because I dread to think how what Almunia's stats would be like this year if a similar comparison was being made. Indeed, I would still probably guess that SZCZ's stats stack up well against most other keepers in the Prem - I would be very surprised if they were not better than those of De Gea and Cech. Friedel is probably the best keeper in the league this season and has been constantly underrated seen his underwhelming spell at Liverpool.
Moreover, SZCZ is starting his career, while Friedel is finishing his - I'm fully confident that SZCZ will step up and become a world-class keeper in the next few years. But, the unavoidable conclusion from all this is that the difference between fifth and third place for Arsenal so far this year has been defensive errors and a lower number of shots on goal saved by our respective goalkeepers. And that SZCZ, for all his confidence, is still learning his trade.
Let's hope that we can turn both these stats round in the new year, and that Spurs undergo their traditional collapse.
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