On the 7th of May 2010, the qualification period for the Judo event at the London 2012 Olympic Games started. More than 4,000 athletes from 153 countries have been chasing the precious few Olympic qualification places.
On May 7th, I started my research project looking at an alternative athlete ranking system for Judo.
The IJF has a qualification system that has been in use for many years, initially just within the EJU but now for the first time as the method of qualifying for the Olympic Games. The system I have been experimenting with has been running in parallel to the IJF system quietly collecting the match results from the 75 qualification events held so far.
The two systems are different at a fundamental level. The IJF reward points to athletes based on the position they reach in the tournament. My system adds or subtracts points after each match. In the IJF system the points awarded are based on the event and the position you reach. My system awards points based on the calculated probability of a player beating their opponent. The idea being that if you beat the best in the world and come first; it should be worth more than beating weaker players and coming first.
One of the categories I have found very interesting is the +78kg category, in part because I am a fan of British fighter Karina Bryant. It is also the smallest category in elite Judo (only 146 athletes). This means it is comparatively easy to watch the category. Also, this category features the infamous Tong Wen of China. Tong Wen (佟文) did not compete for two years after running into trouble with the banned substance clenbuterol; before being cleared and re-entering competition last year at the 2011 Moscow Grand Slam.
Tong Wen is the reigning Olympic Champion and has 7 world gold medals (according to http://www.judoinside.com/judoka/view/12071/wen_tong/ ). So an athlete of this calibre re entering the category late made it very interesting.
From the perspective of my research it was equally interesting as after her first event, my system had her ranked at (if memory serves) #2 or #3 in the category. Where as the IJF system did not have her in the top ten. The reason being that the IJF system only factored in the points from winning that event. Whereas my system took into consideration the fact she beat KONITZ Franziska, POLAVDER Lucija, KOCATURK Gulsah and KIM Na-Young that day. She has fought a total of 21 times and won each one with Ippon (I am excluding the recent default to team mate QIN Qian at the 2012 IJF Masters in Almaty. She is (I believe), the only athlete undefeated in the category.
Yet, Tong Wen is not ranked number one under the IJF system, only third, behind TACHIMOTO Megumi (who she beat at the 2011 World Championships) and QIN Qian (who she has beaten three of the three times they have actually fought). As you can probably guess, my http://rwjl.net system ranks Tong Wen #1 above TACHIMOTO Megumi (#2) and QIN Qian (#3).
I think it is fascinating to compare the systems and this category is proving very interesting to follow.
Once Qualification closes on May 1st 2012, I shall write a report on the project and I would appreciate any and all feedback on the systems and how they compare from whatever perspectives you might have. Be that a player, a coach, a statistician, and administrator or a interested fan.
Please do ask any questions or send your feedback to me at firstname.lastname@example.org