All posts by LanceW

The impact of the Russia ban on Judo

With the Ukraine invasion by Russia, the sporting world has joined nations in placing sanctions on Russia. The IJF has banned Russian Athletes from competing.

In this article we briefly examine the impact this may have on Judo events in 2022.

Hypothesis

Russia is considered a string Judo nation, the men’s team at London2012 was dominant for example. The ban of Russian athletes may weaken Judo events.

Methodology

Using the Webservice::Judobase module and Perl programming language collect all the inscriptions from events across multiple years and sum the events and number of Russian athletes.

Results

Raw initial data:

{
          '2015' => {
                      'Russians' => 815,
                      'total_events' => 59
                    },
          '2016' => {
                      'Russians' => 734,
                      'total_events' => 58
                    },
          '2017' => {
                      'Russians' => 718,
                      'total_events' => 58
                    },
          '2018' => {
                      'Russians' => 824,
                      'total_events' => 62
                    },
          '2019' => {
                      'Russians' => 763,
                      'total_events' => 60
                    },
          '2020' => {
                      'Russians' => 165,
                      'total_events' => 18
                    },
          '2021' => {
                      'Russians' => 492,
                      'total_events' => 38
                    }
        };

Discussion

The data shows a big drop in participation in 2020 and 2021. This could be in due to:

  • Prior/Existing bans
    The doping scandals had already impacted Russian participation and caused calculation of metrics more difficult as athletes have competed under different flags such as RJF (Russian Judo Federation).
  • Pandemic
    2020 to now has been impacted by the COVID-19 pandemic, with event cancellations and travel limitations. Also the 2020 Olympic games were delayed till 2021.
  • Geographic diversity
    A presumption can be made that Russian athletes are attending in larger number the events closer to them geographically. So an exploration of events to see what events Russian’s were attending and compare the impact would be of interest.

Extended data

By including athletes who participated as RUS, RJF (Russian Judo Federation) or ROC (Russian Olympic Committee) we can obtain a better count of Russian athletes.

{
          '2015' => {
                      'Russians' => 815,
                      'total_events' => 59
                    },
          '2016' => {
                      'Russians' => 734,
                      'total_events' => 58
                    },
          '2017' => {
                      'Russians' => 718,
                      'total_events' => 58
                    },
          '2018' => {
                      'Russians' => 824,
                      'total_events' => 62
                    },
          '2019' => {
                      'Russians' => 763,
                      'total_events' => 60
                    },
          '2020' => {
                      'Russians' => 165,
                      'total_events' => 18
                    },
          '2021' => {
                      'Russians' => 523,
                      'total_events' => 38
                    }
        };

This boosts the numbers in 2020, where Russian athletes competed in Tokyo2020 under their Olympic Committee flag.

Another sample we can explore is the numbers from 2022 up till now:

{
          '2022' => {
                      'total_events' => 55
                    }
        };

This is for inscription for all of 2022, taken on 17 March 2022. So majority of inscriptions are till early April; however their are some inscriptions as far ahead as the December 2022.

Surprisingly the data did not show any Russian athletes have participated in events in the first quarter of 2022.

Summary

The invasion of Ukraine by Russia is a terrible thing and the impact of the International Judo Federation banning of the nation is a small triviality compared to the loss of life, harm and lives thrown into turmoil.

However, as trivial it is in comparison; it will have an impact on the sport of Judo.

Further research

It would be interesting to explore the medals won by the Russian athletes along with participation numbers to determine the change in depth of talent in the events.

If you are interested in exploring this, I would like to assist.

Marcus Augustine’s JUDÔ DE BASE website

For those of you who speak Portuguese (or have a translation plugin installed in your browser) Marcus Augustine’s JUDÔ DE BASE website is an interesting resource.

Recent posts have included:

  • Time of the 2022 Grand Slam Fights
  • Principles of Judo Training as an Organized Form of Physical Activity for Children
  • Tel Aviv Grand Slam: analysis of the champions/champions
  • Portugal GP and Paris GS: analysis of champions
  • Performance analysis in Japan
  • How did 430 international judo medalists score?
  • World Championships Juniors 2021 – medalist analysis

Example 1: Zagreb Grand Prix 2021: analysis of the champions/champions

https://judodebase.blogspot.com/2021/09/zagreb-grand-prix-2021-analises-dasos.html

In this post for example Marcus explores the attack rates and suggests :

“…Throwing performed during kumi-kata was the most frequent form of attack in nage-waza , having been used by nine gold medalists…”

Example of a throwing attack during gripping

Another interesting point is the suggestion of a two hands on the back grip was most effective, but least frequent.

Example 2: Principles of Judo Training as an Organized Form of Physical Activity for Children

This article is a review of some Polish research into the participation in Judo by children. Key points mentioned were:

  • When do children start judo?
  • What are the recommendations regarding the frequency and duration of training in this age group?
  • Lesson Objectives
  • Ways of teaching-learning-training 
  • Safety during training

Summary

The site is well worth keeping an eye on; the posts do act as a form of advertising for the online e-learning courses offered; just so you are aware.

This post is not an endorsement for the courses; and is written solely as the site is interesting NOT as an advertisement for the business supporting the blog.

Simple Statistics about recent Olympic Judo Tournaments

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

Athletes393
Contests434
Yuko0
Wazari183
Ippon295
Shido703
Longest contest997
Mean duration233.02
Median duration240.02
Duration in seconds

Rio2016

Athletes390
Contests432
Yuko182
Wazari99
Ippon241
Shido770
Longest contest634
Mean duration211.02
Median duration240.02
Duration in seconds

London2012

Athletes387
Contests331
Yuko204
Wazari91
Ippon173
Shido432
Longest contest600
Mean duration264.02
Median duration300.02
Duration in seconds

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

Tokyo2020Worlds 2021
Athletes393661
Contests434703
Yuko00
Wazari183280
Ippon295537
Shido7031304
Longest contest997936
Mean duration233.02201.02
Median duration240.02205.02
Duration in seconds

Rio2016Worlds 2015
Athletes390723
Contests432765
Yuko182285
Wazari99159
Ippon241443
Shido7701627
Longest contest6342400
Mean duration211.02226.02
Median duration240.02240.02
Duration in seconds

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

Tokyo2020Worlds 2021Rio 2016Worlds 2015
1.611.851.782.12

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

Tokyo2020Worlds 2021Rio 2016Worlds 2015
0.670.760.550.57

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.

  1. Athletes are more cautious at the Olympics
  2. 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).

How big is the IJF World Tour?

The IJF world tour consists of the elite level tournaments in cities around the world. This brief post shares some rough calculations on the size of the tour in terms of distance traveled.

Summary

IJF World Tour Distances (from/to London)

  • 3,181 km Grand Prix Portugal 2022
  • 684 km Paris Grand Slam 2022
  • 7,113 km Tel Aviv Grand Slam 2022
  • 7,078 km Tbilisi Grand Slam 2022
  • 5,823 km Antalya Grand Slam 2022
  • 6,422 km Kazan Grand Slam 2022
  • 960 km Dusseldorf Grand Slam 2022
  • 13,945 km Ulaanbaatar Grand Slam 2022
  • 2,898 km Budapest Grand Slam 2022
  • 2,675 km Zagreb Grand Prix 2022
  • 10,468 km Tashkent World Senior Championships 2022
  • 10,950 km Abu Dhabi Grand Slam 2022
  • 8,029 km Baku Grand Slam 2022
  • 19,125 km Tokyo Grand Slam 2022
    Total distance: 99,351 km

Methodology

Taking the IJF calendar, a city is chosen and a latitude and longitude determined (center of the city) using an interface to the OpenStreetMap projects GeoCoding API.

Using the city of London as the start point, a calculation distance to and from the destination city using a library (GIS::Distance) using the “Haversine” formula.

These are totaled and present as above.

Carbon calculation

Knowing the distance covered, we are able to make a very naive calculation as to how much co2 is generated. This was done using a basic 259 g/km pessimistic co2 per km per flight (https://en.wikipedia.orghttps://en.wikipedia.org).

Using this it was possible to estimate a total of 25,731 kg Co2 for one athlete competing from London in the UK.

Discussion

This exercise of calculating the total distance the tour is an interesting aside. The carbon calculation is a very rough calculation but does set a simple baseline should people want to use it.

An interesting point to note was that competing from central Europe (for example IJF headquarters city Budapest) significantly decreased the total distance. Other nations such as New Zealand for example the distance is considerably larger.

We already know anecdotally that athletes from countries like New Zealand base themselves in Europe to minimize costs.

The calculation is based on round trips to and from London. Athletes already group events (the “asia tour” and “south america tour” have been unofficial features of international Judo for a long time.

A interesting exercise might be to calculate total distance on various permutations of the tour as a point to point tour? This would conceivably decrease the distance (and carbon cost). It might also be an interesting logistical change and opportunity for the Judo community.

Alternative transportation methods would be interesting also. Along with perhaps a time based calculation. Using a route planning algorithm to API might be able to provide a more detailed calculation of distances from a home location, to airport, to venue, etc. Potentially incorporating train, boat and bus transportation methods.

I hope this was an interesting read, I would be interested in your thoughts and opinions. If anyone is interested in taking this exercise a further, please do drop me an email (lw@judocoach.com)

What are the top Judo nations?

Determining which nations are the strongest in Judo is a complicated calculation. In this article we shall approach this by looking at Rio2016 Olympic games.

Technology makes investigating this subject somewhat easier than in earlier times. The IJF operates the http://judobase.org website, which includes all data from IJF events since 2009, including the Olympic Games in Rio.

Medals

  • Japan
  • France
  • Russia
  • Italy
  • USA

Wins

  • Japan
  • Slovenia
  • Italy
  • Azerbaijan
  • France

From these two metrics we can easily identify that Japan tops both lists, France and Italy appear on both lists as well. USA does not appear on the second list, but only just they are 6th on that list.

These two metrics suggest that Japan and France are the strongest nations.

Other metrics need to be considered also, for example number of athletes qualified for the event (excluding the home nation Brazil that had automatic qualification):

  • France
  • Japan
  • Germany
  • Mongolia
  • Russia

Again, France and Japan top the list, which could infer depth of talent. France and Japan were the only two nations that had 14 athletes compete in Rio.

More investigation is required clearly, but even this simple examination can give some information and importantly raise questions around the topic.

 

Optimal competition scheduling.

In 2016 a paper was published by Emerson Franchini, Monica Y. Takito, Rodrigo M. da Silva, Seihati A. Shiroma, Ursula F. Julio and myself.

Optimal Interval for Success in Judo World Ranking Competitions” is an investigation into the number of days/weeks between competitions for Judo athletes competing on the IJF senior circuit.

The study concludes:

“Optimal interval period between successive competitions varies according to competition level and sex: shorter intervals (6-9 weeks) for females competing at the lowest competition level (Continental Open), for most of the competitions the 10-13 week interval was detected as optimal for both male and female athletes (Grand Prix, Continental Championship and World Championship), while for the ranking-based qualified male competitions (i.e., Masters and Olympic Games) a longer period (> 14 weeks) is needed.”

The paper suggests that female athletes are competing approximately once every 10-13 weeks.

In terms of athletes development and planning the finding that the optimal is different between male and female athletes is interesting and should be factored into athlete competition scheduling.

Equally, it is worth investigating if your less experienced athletes should be competing more frequently; with the time between competitions increasing as they progress up the ranks.

This does however assume that the increased time between competitions is related. We should research into the subject more fully to understand the area more thoroughly.

 

2016 Junior WRL Statistics

The IJF World Ranking Lists are valuable sources of metrics for researchers. This article includes some simple statistics gained from the 2016 IJF Junior WRL.

2016 IJF Junior Athletes

These charts can make it easy for interested people to visualise the dispersal of athletes across both weight classes and continental unions.

From this you can easily see that the W-57kg and M-73kg categories are the most popular and that majority of athletes are from the EJU. Comparing Male to Female you can see a difference in the overall shape of the charts. It would appear that the females have a more even distribution of athletes across females with male athletes being skewed towards the lighter weights.

As coaches, researchers or administrators these simple statistics might be useful for decision making processes. For example event organisers might identify the need to attract more heavyweight junior males to participate in events.

The IJF world ranking lists are freely available from the IJF.org website and this site would welcome contributed articles based on investigations into the Cadet, Junior and Senior IJF World Ranking Lists.

Judobase.org

The first big european event in the Rio2016 qualification period occured on the weekend and it is a good time to explore the data we now have freely available from the IJF.

This year The International Judo Federation (IJF) released the Judobase.org website. This site has been in development for sometime and now is available, for free, to anyone. The site is similar to the venerable judoinside.com site, with a couple of important differentiators.

1) It is created from the official IJF data systems.

What this means is that this is the “official” source of data, and coming direct from the IJF IT systems it should be more accurate.

It does however mean that it only covers the IJF events, so judoinside remains the go to site for a complete picture of athletes career. The JudoBase site will not tell you if/when a player won their national championships, etc.

2) Scores.

Judobase being intergrated into the IJF data systems is able to capture and include scoring data. So you can see when a score happens in each fight (only available in more recent events). So it has more detail.

3) Video.

Once again being integrated has it’s advantages, the video from the official cameras is being encoded and uploaded with only a small delay to Judobase.org. You can click on a contest and watch the video (whilst looking at the scores) and really get the data you need.

4. WRL Integration

The judobase system already includes the athletes world ranking list (WRL) data. This is currently coming from the manual systems but will I imagine become the canonical source for ranking data.

So what can we discover?

The statistical side of Judobase.org is not very mature, it is really only an indication of what is possible. I would hope that the readers of this blog would quickly find ideas and share them so that the Judobase system can automatically generate relevant data for enthusiasts, fans and researchers.

 

So the latest event at the time of writing is the Budapest Grand Prix; and this is available at http://judobase.org/#/competition/profile/1166

 

A new Olympic qualification cycle begins, Rio2016

On May 31st 2014, the qualification period for the Rio2016 Judo tournament began. This is the start for the nations and athletes of the final build-up to the pinnacle event in Judo, the Olympic Games. judobase_bannerAnd this site will be following along closely and exploring the numbers. The qualification system for Rio2016 is similar to that of London2012, in simple terms the 22 men and top 14 women in the world get entry into the games. Then a quota system is used to select players from the ranking list from a wide variety of nations. As with the last Olympic cycle, the IJF Senior World Ranking List is the most important element in an athletes qualification chances.

 

As with the last cycle we expect to see players approach qualification in different ways. Teams struggled with qualification last cycle and no doubt will again. Although we hope that they have a better understanding of the system than last time around. Only the British have an excuse for not understanding it as last time round they did not need to qualify players; this time the Brazilians have that advantage.

 

The WRL also affects the seeding at each event, and for the games itself. As such, it is really important for athletes to monitor the WRL and manage their entries to try and get as high on the list as they need to be. The next 6 months will be interesting to see how the better teams have chosen to distribute the athletes. We have seen many of the big names getting rehab since London and many have obviously been taking time out and getting set for the trials and traumas that follow.

 

I personally am very interested in how strategic entry into events affects the WRL. So, stay tuned as this site will try and be very active for the next two years leading up to Rio2016. A new resource is available to us now also, the newly launched IJF http://judobase.org site contains the absolute best data direct from the IJF on every event (its a IJF only http://judoinside.com ).

 

Lance

Scoreboard activity at 2013 Paris Grand Slam.

Day One:

Scoreboard actions: 1137

  • Ippon (minute 1): 16
  • Ippon (minute 2): 30
  • Ippon (minute 3): 37
  • Ippon (minute 4): 29
  • Ippon (minute 5): 34

Total: 146 Ippon Actions. The Ippon.org data shows that 80 Ippons were recorded in the final record, so 66 times Ippon was put on the board and later removed for whatever reason.

The total number of scores per minute including ippon broke down as:

Total Scores: 913

  • Minute 1: 163
  • Minute 2: 248
  • Minute 3: 204
  • Minute 4: 142
  • Minute 5: 156

The next post will be the overall numbers for the event including day 2.