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# Clap skates make it unnecessary to run the 500 m twice

06 March 2008
Speedskaters who finish in the outer lane in the 500 m race no longer have an advantage over those who end in the inner lane. The reason that this has changed is the arrival of the clap skate. Econometrists at the University of Groningen have established that statistically, the difference between the inner and the outer lanes no longer exists in 500-metre races. The clap skate has reduced the 95% certainty of a difference in time to an interval of -0.008 and +0.032.

Until 1998, the 500 m race in speedscating was run only once, and participants drew lots to see who started in the inner lane and who in the outer lane. It was thus a matter of chance who would finish in the inner lane. Many skaters could not make the turn due to their high speed, flew completely or partly out of the bend and thus lost the race. Based on calculations by the Norwegian professor Nils Lid Hjort, the ISU and the IOC decided in 1998 that the 500 m race should be run twice, with the participants taking it in turns to start in the inner and outer lanes. Hjort calculated that it could be stated with a certainty factor of 95% that the difference between a skater’s inner and outer lane times lay between +0.016 and +0.064 seconds.

### Difference in time reduced

Econometrists at the University of Groningen have now established that statistically, the difference between the inner and the outer lanes no longer exists 500-metre races. Since the introduction of the clap skate in 1996, the 95% certainty of a difference in time has been reduced to an interval of -0.008 and +0.032.

### Racing round the inner bend

Skating experts had already noticed that the real sprinters currently ‘attack’ and ‘overcome’ the final inner bend as easily as the outer one. Statistically, the difference between the inner and outer lanes no longer exists even on the superfast high altitude rinks at Calgary and Salt Lake City. Thus Hjort’s argument no longer applies today.

### Risks of immediate disqualification

We’ll have to wait and see whether the IOC can dispense with running the 500 m twice at the Olympic Games. Perhaps it would be an idea to keep the two races and to take the best time instead of adding the two times together. A stupid mistake in one of the races would then no longer mean the immediate end of any chance of a medal.

### Note for the press

Information: Prof. Gerard Sierksma, tel. 050-525 0533, e-mail: g.sierksma@rug.nl

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