Dipl.-Stat. Arno Fritsch
TU Dortmund
Faculty of Statistics
Mathematical Statistics with Applications in Biometrics
Tel.: +49 231 755-4391
Fritsch@statistik.tu-dortmund.de
The ranking can be downloaded at:
http://depot.tu-dortmund.de/get/s2sscy
During his career Rudolf Kargus saved 23 penalties. That’s a record. But does this really make him the penalty-killer in the history of the German premier league? After all, there are not many goalkeepers in this league who let through more penalties than he did. And maybe it was just luck because he had to take on many bad penalty-takers. Now a team of statisticians of TU Dortmund produced a “fair” ranking. This list takes account of the real individual ability of all 280 goalkeepers in the history of the German premier league.
Nahmen 3828 Elfmeter ins Visier: Björn Bornkamp, Prof. Katja Ickstadt und Arno Fritsch (from left to right).
Prof. Dr. Katja Ickstadt, Dipl-Stat. Björn Bornkamp and Dipl.-Stat. Arno Fritsch from the Faculty of Statistics carefully examined 3,828 penalties, assisted by their colleague Dr. Oliver Kuß from the Institute for Medical Epidemiology, Biometry and Informatics at Martin-Luther-Universität Halle-Wittenberg. That includes all penalties from the seasons 63/64 up to 07/08. 264 miskicks or shots against the post were not considered, as it was all about the goalkeepers’ performances. And the simple rate of saved penalties doesn’t reveal the individual ability. Otherwise Karl Eisenhofer, for example, would be the penalty-killer par excellence, as he won 100 percent of his penalty duels. But during his two German premier league matches for Eintracht Frankfurt he only had to deal with one penalty which he promptly saved. But does that make him better than, for example, Jean-Marie Pfaff who at least saved 55 percent of eleven penalties?
To solve this problem, the Dortmund statisticians applied an extension of the so-called logistic regression model. This complex mathematic procedure enables it, to consider how much information is available about each goalkeeper when calculating the individual ability to save penalties. In doing so, the statisticians proceed on the assumption that the ability of all goalkeepers to save penalties is evenly spread. There is not much information about goalkeepers who participated in only a few penalties. Therefore their calculated ability is close to average. With regard to goalkeepers who participated in a lot of penalties, there is more information, so that the probability to save penalties is close to their real rate of saved penalties. The strength of the scorer is also included in this “penalty-killer formula”. Another advantage of this formula is that the researchers have the chance to consider factors like the particular season (maybe it was easier to save a penalty in the past?) or the home advantage (is it relevant for the penalty?).
And the results? First of all, the statisticians were able to determine that season and home advantage have no bearing on the probability to save a penalty. To save a penalty is as difficult as ever, regardless of the fact whether the goalkeeper stands between the posts at home or away.
According to the “fair” ranking methods of the Dortmund statisticians, Rudolf Kargus can still claim the title for himself. National goalkeeper Robert Enke comes in second. It might be interesting for Joachim Löw that with the 88th place Tim Wiese is average. With regard to penalties the competition for the position of goalkeeper in the national team therefore seems to be over – at least with regard to the statisticians. Even Jens Lehmann shouldn’t hope for statistic support as he trails behind on the 233rd place. Third-best penalty-killer in the history of the German premier league is Andreas Köpke.
And the “red lantern”? Followed by the last two competitors with regard to penalties is Jürgen Rynia. Between 1969 and 1972 he was the goalkeeper of Borussia Dortmund. Last but one is Walter Junghans. During his career he succeeded Sepp Maier twice. 1979 as Bayern-goalkeeper and 2008 as Bayern-goalkeeper trainer. But where penalties are concerned he lies ahead. In the penalty-killer-ranking Germany’s goalkeeper of the century of all people comes last.