OBO at 1998 Europeans

OBO at 1998 Europeans

By Sandra Loosemore (January, 1998)

This is a followup to my earlier articles, If It Ain't Broke, Don't Fix It and The Truth About OBO, which describe the perceived problem of flip-flops in the standings and the OBO proposal that Ottavio Cinquanta and other ISU officials have been advocating as a "solution".

A simulation of the OBO scoring system using the marks and skating orders from the 1998 European Championships has turned up more instances of flip-flops and questionable results.

The ladies short program produced this interesting situation, involving a near-tie between three skaters. Because these skaters finished near the bottom of the rankings, this may not seem particularly critical to the outcome of the competition, but in fact it does have an affect on which skaters made the cut for the free skate, which would have been different under OBO than under the current ordinal system. This example also shows the extreme instability of the OBO tie-breaking mechanism in some circumstances.

After Katerina Blohonova skated, her marks put in next-to-last place over Golovatenko, like this:

 5.              Katerina BLOHONOVA   1   11  <=== new
 6.          Jekaterina GOLOVATENKO   0   11

These relative placements remained unchanged until Anina Fivian, the third of the competitors involved in the tie situation, skated. Her marks caused Golovatenko to move ahead of Blohonova, into a tie with Fivian.

 7.                    Anina FIVIAN   1   16  <=== new
 7.          Jekaterina GOLOVATENKO   1   16  <=== changed
 9.              Katerina BLOHONOVA   1   15  <=== changed

The next skater was Valeria Trifancova. Although her marks were generally much higher than the three skaters we're looking at, one of the judges had her behind Blohonova. This caused a three-way tie at the bottom of the standings:

 8.                    Anina FIVIAN   1   16
 8.              Katerina BLOHONOVA   1   16  <=== changed
 8.          Jekaterina GOLOVATENKO   1   16  <=== changed

After Noemi Bedo skated, the judges gave her marks that put her in last place. However, she won one judge each over Fivian and Blohonova, which caused Golovatenko to break out of the tie:

10.          Jekaterina GOLOVATENKO   2   25  <=== changed
11.                    Anina FIVIAN   2   24  <=== changed
11.              Katerina BLOHONOVA   2   24  <=== changed

Similarly, Salome Chigogidze won one more judge over Blohonova than Fivian, causing their tie to be broken, while Golovatenko remained in front:

15.          Jekaterina GOLOVATENKO   3   32
16.                    Anina FIVIAN   3   31
17.              Katerina BLOHONOVA   3   30  <=== changed

But, when Kaja Hanevold skated, the tie returned:

19.          Jekaterina GOLOVATENKO   4   40
20.                    Anina FIVIAN   4   36
20.              Katerina BLOHONOVA   4   36  <=== changed

And finally, it was broken again after Marta Senra skated:

23.          Jekaterina GOLOVATENKO   5   48
24.                    Anina FIVIAN   5   44
25.              Katerina BLOHONOVA   5   43  <=== changed

In summary, Blohonova was originally in front of Golovatenko and actually "won" the one-by-one comparison against her, but wound up finishing two places behind her and failed to finish in the top 24 as a result. Blohonova also moved in and out of a tie with Fivian five times during the course of the event! In the actual competition, it was Fivian who failed to make the cut rather than Blohonova.

Another very curious effect of the OBO scoring system is that it reversed the placements of the 2nd and 3rd place finishers in this competition segment from the actual results under the current ordinal system. The ordinals for the two skaters involved are:

Surya BONALY       5 4 2 2 5 2 1 1 4
Irina SLUTSKAYA    2 3 3 1 4 3 4 2 3

Under the current scoring system, Bonaly had a majority of five votes for second place, while Slutskaya had only three votes for second place or better. However, under the OBO simulation, Slutskaya was placed ahead of Bonaly, primarily because Slutskaya "won" over Bonaly by a 5-4 split in a direct comparison of their marks.

In the OBO simulation of this event, there were also instances in both the men's and ladies' free skate where skaters moved in and out of ties as a result of the placements given to other competitors.

In the men's event, Patrick Meier was initially ahead of Ivan Dinev, then tied with him, and then ahead of him again. Part of the problem here was that the Polish judge gave both competitors identical marks of 5.3/5.3 and the rest of the panel was equally split between them, so that they each scored a "win" over the other.

In the ladies' event, Krisztina Czako's marks put her in a tie with Julia Lautova, with Yulia Vorobieva also having the same number of "wins" but one fewer "judges in favor":

 1.                 Irina SLUTSKAYA  21  182
 2.                Tanja SZEWCZENKO  20  181
 3.                 Elena LIASHENKO  19  167
 4.                 Julia SOLDATOVA  18  168
 5.                 Krisztina CZAKO  16  136  <=== new
 5.                   Julia LAUTOWA  16  136  <=== changed
 7.                 Yulia VOROBIEVA  16  135

However, when Surya Bonaly skated, Czako scored a "win" over her, while Lautowa did not, moving Czako definitely over Lautowa, who was moved into another tie with Vorobieva. Perhaps most surprisingly, in spite of Czako's "win" in the one-by-one comparison with Bonaly, she still wound up behind Bonaly in the final standings due to the OBO tie-breaking rules! In the actual competition using the current scoring rules, Bonaly finished behind Czako.

 1.                Maria BUTYRSKAYA  23  207
 2.                 Irina SLUTSKAYA  22  191
 3.                Tanja SZEWCZENKO  21  190
 4.                 Elena LIASHENKO  20  176
 5.                 Julia SOLDATOVA  19  175
 6.                    Surya BONALY  17  142  <=== new
 7.                 Krisztina CZAKO  17  141
 8.                   Julia LAUTOWA  16  139  <=== changed
 8.                 Yulia VOROBIEVA  16  139  <=== changed

Notes

The program used to perform these simulations was written in ELisp, the extension language for the text editor Emacs. It is available at http://www.frogsonice.com/skateweb/obo/obo.el. This file also contains the input data that was cut-and-pasted from the results and starting orders published on the WIGE 1998 Europeans web page.

Likewise, the full results of the simulations are also available on the web at http://www.frogsonice.com/skateweb/obo/obo-euros.txt.