Tokyo2020 was just last year (2021); in this article we want to share some simple descriptive statistics to compare Tokyo to Rio and London.
Tokyo2020
| Athletes | 393 |
| Contests | 434 |
| Yuko | 0 |
| Wazari | 183 |
| Ippon | 295 |
| Shido | 703 |
| Longest contest | 997 |
| Mean duration | 233.02 |
| Median duration | 240.02 |
Rio2016
| Athletes | 390 |
| Contests | 432 |
| Yuko | 182 |
| Wazari | 99 |
| Ippon | 241 |
| Shido | 770 |
| Longest contest | 634 |
| Mean duration | 211.02 |
| Median duration | 240.02 |
London2012
| Athletes | 387 |
| Contests | 331 |
| Yuko | 204 |
| Wazari | 91 |
| Ippon | 173 |
| Shido | 432 |
| Longest contest | 600 |
| Mean duration | 264.02 |
| Median duration | 300.02 |
Quick observations
You can see that the number of athletes is pretty stable between Rio and Tokyo; London being slightly smaller. The duration of contests has grown consistently.
The number of Ippon has trended upwards; and we have lost Yuko. Wazari has increased also. The scoring changes affect this, no more yuko. Interpretation of rules affects it also.
Shido is interesting as it has not followed the same trend:
432 -> 770 -> 703
This would be an interesting area to explore; perhaps along with the other scores and when rule changes have been implemented. Is this a result of the rule changes?
Comparison to preceding world championships
| Tokyo2020 | Worlds 2021 | |
| Athletes | 393 | 661 |
| Contests | 434 | 703 |
| Yuko | 0 | 0 |
| Wazari | 183 | 280 |
| Ippon | 295 | 537 |
| Shido | 703 | 1304 |
| Longest contest | 997 | 936 |
| Mean duration | 233.02 | 201.02 |
| Median duration | 240.02 | 205.02 |
| Rio2016 | Worlds 2015 | |
| Athletes | 390 | 723 |
| Contests | 432 | 765 |
| Yuko | 182 | 285 |
| Wazari | 99 | 159 |
| Ippon | 241 | 443 |
| Shido | 770 | 1627 |
| Longest contest | 634 | 2400 |
| Mean duration | 211.02 | 226.02 |
| Median duration | 240.02 | 240.02 |
The World Championships as we can see are larger events, the Olympics having restrictions on the numbers who can attend. This affects the number of contests and number of scores.
We would have to do some more sophisticated analysis to see some patterns.
The duration of contests is interesting and might suggest some investigation areas. There seems to be an anomaly at the world championships in 2015 where there was a 2400 minute contest!?
Shido per contest
| Tokyo2020 | Worlds 2021 | Rio 2016 | Worlds 2015 |
| 1.61 | 1.85 | 1.78 | 2.12 |
This, though naive, does show a decline in the number of penalties per contest. In the sport I think we all wanted to see fewer penalties; so the changes to the sport could be said to be working.
Ippon per contest
| Tokyo2020 | Worlds 2021 | Rio 2016 | Worlds 2015 |
| 0.67 | 0.76 | 0.55 | 0.57 |
We can see there is an increase in Ippon scored over time. The number is lower at Olympics than at the World Championships. There are more than one possible theories for this.
- Athletes are more cautious at the Olympics
- There is a broader range of ability at the World Championships
Summary
This article has some very basic analysis of the recent Olympic Judo events. The pattern could indicate that the number of penalties is decreasing and ippon increasing. This might indicate our sport is becoming more exciting?
It is important with this sort of descriptive statistics is to appreciate the bluntness of what the numbers show.
They may cause someone (you) to be intrigued by these statistics; leading to some detailed investigation.
If you are interested in exploring this sort of data; please do contact me; or explore the wider Judo research community (the IAJR is a good starting point).