Tag Archives: Judo

Statistical Summary of Judo at 2006 Commonwealth Judo Tournament.

The text below is the result of the pilot study that was the inspiration for my BSC. research project at University of Bath on the Beijing Olympic games Judo event. The study looks at the attack rate of players in the 2006 Commonwealth Judo tournament and their success rate. I have posted it previously on www.judocoach.com/judo but have decided to add it here as it is in keeping with the subject of this site.

Summary of the 2006 Commonwealth Judo Tournament.

At the 2006 Commonwealth Tournament, a study of the attacks,
scores and durations of bouts was made. Eighty-nine bouts were successfully notated. The results
have been collated and analysed and this document is a summary of the findings.
Full details on the study and methodology are being developed so to make them available to
everyone. The hope is that this will encourage others to conduct similar studies.
Descriptive Statistics
Total Fights 89
Total Scores 139(no penalties)
Total Attacks 1305
Total Penalties 100
Total Segments 732
Total Match Time 259Minutes 101.45Recovery time in fights
Total Actual Time 360Minutes 1.14Recovery per fight
Total Possible Contest Time 432Minutes 0.14Between segments
Fights won by Blue 47 53%
Fights won by White 42 47%
Fights won by person who attacks most 61 69%
Fights won by person who attacks least 28 31%
69 33%
21 10%
61 29%
58 28%
Total: 209
Scores per fight (AVG) 1.56
Attacks per fight (AVG) 14.66
Penalties per fight (AVG) 1.12
Segments per fight(AVG) 8.22
Of Actual time on mat 72%
Of time allocated 83%
Scores per segment 0.19
Attacks per segment 1.78
Penalties per segment 0.14
Ippons Scored
Wazaris Scored
Yokus Scored
Kokas scored
(incl Penalties)
Findings for players and coaches:
By averaging out the results of the data collected, we are able to describe an average Judo bout at
the Commonwealth Tournament level.  An average fight at commonwealth level consists of the
Each match is approximately four minutes long, and consists of eight “segments” of action.
Each segment of approximately 30 seconds in duration, with 14 seconds between each segment.
Within each segment we can expect 1-2 attacks only before Matte is called.
We can expect a score every 7-8 segments, this score will be Ippon 1/3rd of the time. The other
two thirds of the time it will be divided almost equally between Koka & Yoku. Wazari will be
scored infrequently (only 10% of the overall scores).
Given this description of an average match, we are able to develop coaching strategies and
training sessions to best simulate commonwealth level Judo. Sessions could be developed
following approximately the following format.
Endurance drill:
Athlete attacks at near maximal level for 30 seconds.
They then recover for 14 seconds
The above two steps are repeated 8 times.
This drill helps develop the athletes ability to give maximum effort for entire match for difficult
Tactical Drill:
Athlete fights for grip for 10 seconds
Coach calls “NOW”, and athlete must make one large attack
Athlete then continues to grip fight for 10 seconds
Coach calls “NOW”, and athlete must make one large attack
Athlete recovers for 14 seconds
Repeat above steps eight times.
This drill trains the athlete to make maximum use of the available time. Minimising risk of
passivity attacks whilst keeping energy expenditure minimal.
Active defence Drill:
Athlete is attacked constantly for 30 seconds, they must only defend.
At 10 seconds the coach shouts “NOW”, the athlete must make some form of positive attack.
At 20 seconds the coach shouts “NOW”, the athlete must make some form of positive attack.
At 30 seconds the coach shouts “NOW”, the athlete must make some form of positive attack, this
attack must be “terminal”, concluding on the floor or outside safety area.
Recover for 14 seconds
Repeat above steps eight times.
This document is a very basic analysis of a small amount of information from the 2006
Commonwealth Tournament. It is hoped that this documents shows how this form of study and
analysis can provide interesting insights which can be applied to training programme
Further analysis of the data is under way and a more detailed document will follow.
The use of simple mean averages provides generalised information which provides only an
indication of general trends in the data analysed. This needs to be considered when developing
training programmes.
For example, the four minute figure mentioned in this document is a mean average of all the
fights recorded. The range of durations went from a few seconds to over twelve minutes spent on
the mat.
Similarly, the mean averaged number of segments, covers all stages in a competition. Initial
examination of the data showed a visible change in contest structure in the later stages of a
category. This included more segments, hence more attacks, but with each segment being sorter.
Your athlete may be better served by drills that followed this pattern over the average format of a
Commonwealth level Judo match
Full details of this research are available via the www.JudoCoach.com
website and/or by contact the author, Lance Wicks, directly at the email
address: lw@judocoach.com. Fellow researchers are invited to contact Lance
Wicks to source the data and digital copies of the notation forms, etc.
It is hoped that this research will act as a catalyst, encouraging further
research within the sport by researchers both with and without experience.
Kia Kaha, Kia Toa, Kia Manawanui
Be brave, Be Strong, Be Perservering
(Old New Zealand Maori Saying)
(c)2006, Lance Wicks. www.judocoach.com lw@judocoach.com

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JudoMetrics: Re-stating my assumptions.

Recently I have been involved in two conversation threads related to, but seperate from this site. The first was about my BSc. research project notating the attack rate of Judo athletes in the Beijing Olympic Judo Tournament. The second is a thread about Talent Identification in Judo and generally. Also there have been a couple of posts in the Judo Blogosphere about Malcolm Gladwells “Outliers” book that helped inspire this post.

In both conversations my response has been that if we can identify the factors needed, then we should be able to predict future results. As per Max Cohen in the movie Pi, I decided to “re-state my assumptions” as I think it will help set the context for this website better for visitors.

Assumption 1: If we can identify the right metrics, we can predict results.

So, what I mean is if we knew what caused a player to win a Judo match, then we could track this for two players before (or during) a match and predict the victor.

Evidence: If player 1 has beaten player 2 ten times in ten matches, then we could fairly comfortably predict that player 1 will beat player 2 in their next match. If player 3 has won all their pre-liminary fights by Ippon we can start predicting that Player 4 will lose to player 3 by Ippon.

The “ah yes, but…“:

The problem is that Judo is very complex, (argueably) more so than other sports. In Rugby Union for example, the team that retains possesion and territory will generally win. It is not always the case, but it is a performance metric that works in a sport where there are (again argueably) more variables to consider than in Judo. There are 30 players not 2 (more if you count subsitutions), there is weather conditions etc. Yet the simple metrics of possesion and territory can give a pretty good prediction of results.

So rather than say it is not possible to predict Judo using metrics, I argue that it is possible and that we just have yet to research well enough to find the metrics that matter.

Whether we ever are able to measure enugh worthwhile information to predict results of individual matches… we shall see. Also, whether we will be able to use these metrics for anything other than academic use is questionable also. I am not sure that we can coach players to fight certain ways as the statistics say it will result in a victory. So perhaps Judo metrics will never be an “applied science”.

Personally, I suspect that performance metrics will prove useful.
Assuming we can discover the right things to measure and we are able to interpret the results appropriately. “Knowledge is power” they say, we already know that countries like Germany and France are compiling information/knowledge about the players their players will meet, in terms of throws they use etc. It is not that big a leap from this to them also collecting statistics on throw frequencies and scoring ratios etc.

I suspect that we could increase our success in Judo if we were able to analyze more knowledge (metrics) about players from other countries.

Talent ID and Judo Metrics

I believe that we can predict the result of matches through Judo metrics, I also believe that we can/could predict who would be a good Judoka; if we can assess enough variables. We may not be able to predict accurately, but we could identify likely candidates. We have some evidence to support this via the soviet era sport and more recently in China.


It may well be the case that JudoMetrics is as realistic science as Psychohistory and it may well be “bunkum“, but IMHO it is worth researching further, at least to a point where we have a better view of it and can decide if it is the future or snake oil. It may be that on this site I am pursueing an idea as mad as Max Cohen’s in Pi…  time will tell.

The International Judo Federation (IJF) Ranking system.

This weekend (25 January 2009), the first of the events of the IJF ranking system will be held. The new system of ranking is important as it shall decide who can attend the London 2012 Olympic Judo tournament. In this post we shall take a good look at the system…

IJF Ranking Points System.
IJF Ranking Points System.

As you can see from the table, athletes are awarded ranking points depending on the position they reach and the event they are competing in.

So, win the World Championships and get 500 points, win one of the new masters events and get 400. Third in my native OJUs and you’ll get 32 points.

Come 30th April 2012, the players ranked in the top 22 for men, or top 14 for women (per category) are the qualifiers for the London Olympics.

The system gets more complicated from here on in, only the top 5 results per year are counted. So if you were to win the 2009 World Cup, Grand Prix, Grand Slam, Masters,World Championships and the OJUs; you would receive 1400 points. However, these points will not actually be worth 1400 in 2012, they will in fact only be worth 350 points as the points “degrade” by 25% per year (The dividing line is the beginning of the month in which the tournament ‘s first
competition day, was held).

Now the rest of the places in the games will be chosen by the Continental unions. Each continental union gets half the number of National Federations affiliated to each that union. So the EJU which has 50 member states and would receive 25 places for athletes who do not make the top 22/14.  These will be decided basically by the top points scorer in the continent, until the fill quota is used, with a maximum of two athletes per category being qualified by this method.

The new system starts with all athletes having zero points. So this weekend is the first opportunity for them to start qualifying for 2012.
It is however based on the result in the tournament not on the athletes you beat. If you happen to have the easiest draw in history at the World Championships it is worth just as much as if you fight all the top athletes in your category. Will this work well is to be decided, I have not seen what research was done in deciding on this system.

Personally, I am more in favour of a system like the ELO system used in Chess (and online gaming like Xbox Live). The ELO system takes into consideration the probabilities involved in one athlete beating another. If a player who is much lower on the ELO ranking beats a higher ranked player, they receive a larger number of ranking points than if they beat someone below them. It is my intention, if I can obtain all the draw sheets, to run the ELO system and monitor the rankings to see if it ranks athletes over the 4 years differently.

Sikorski et al. (1987).

In the area of research into the metrics of Judo, the work of Sikorski, Mickiewicz, Majle and Laska from 1987 is probably the most cited.

Their 1987 paper “Structure of the contest and work capacity of the judoist” has been referenced and used as the basis for further research by the likes of Franchini and Sterkowicz. The work describes both the structure of matches and also the physiological elements and is of interest to researchers and coaches today.

The paper identified the periods of work (Hajime – Matte) and found that these were usually no longer than 30 seconds in duration (decreasing as the match progresses). The breaks between the work periods was on average 10 seconds (increasing as the match progresses). The trend of the duration of the work periods and rest periods continues until they are near equal in the final minutes of a match.

The paper also identified the most prevalent techniques:

  • Seoi Nage
  • Ko Soto gari
  • Uchi Mata
  • O Uchi gari
  • Ko Uchi gari

The study also identified that the most important tactical factor was the ability to cause an opponent to be penalised for passivity.

In my pilot study in 2006 of the Commonwealth Judo Tournament, almost 20 years later, the 30s per work period was near that of Sikorski et al. Although the 30 second figure from the original paper is taken from the conclusion (abstract), where as in the actual text the average is described as being 25 seconds. Perhaps indicating that in two decades the average work period increased by 5 seconds? This may also be supported by the average length of the rest period being 14 seconds in 2006.

Another factor to consider is the rule changes between 1987 and 2006.
Also the level of competition observed, perhaps the work period is affected by the level of athletes competing.

These observations were in part the inspiration for my current analysis of the 2008 Beijing Olympic Judo Tournament. Again, there are factors that prevent an ideal comparison as the Olympics is a very different tournament/event.  The 20 year progression in the sport and the rules may have affected the results.

If the results are quite different, what does this suggest? If they are similar what does this suggest?

In summary, the Sikorski et al (1987)  paper is important reading for anyone looking at Judo analysis and metrics. The paper has been citedin many other works and seems to form the basis for much of the later work in the area. Essential reading perhaps?


2006 Commonwealth Judo Tournament Statistical Analysis.

In 2006, I (Lance Wicks) notated two days of Judo at the 2006 Commonwealth Judo Tournament.

The purpose of the notation was to do a statistical analysis looking to prove the hypothesis that the number of attacks made by a player had a correlation with winnning the match. The results are shown below:
Summary of the 2006 Commonwealth Judo Tournament.

The notation was done manually with a custom paper form. Each attack was recorded as were scores.
This data was then entered into a spreadsheet for analysis.
As the document above indicates, a relationship was shown between attacking more and winning. Included with the results is a set of simple training drill ideas that have been designed to help prepare Judo athletes for the format of a tournament of this type.

Hello world!

Hello everyone,

this is the beginning of a new web project by Lance Wicks.

The idea here is to develop and share Judo analytical tools for the statistical analysis of Judo competitions. The initial project this site will be covering is a notational analysis of the Beinjing 2008 Olympic Judo competition. This is being hand notated and the results will be shared here.

Please visit regularly as the site shall start shanging rapidly over the next few months.