by Elie A. Morrell, Shichidan

Many of the calls by the referee in a judo contest are those associated with scores resulting from throwing actions. To that end, this paper discusses the disparities in the interpretation of throwing score requirements that appear to exist widely today. Each of the four throwing scores will be discussed in detail.

The opinions and conclusions cited in this paper are strictly those of the author and are based on personal observations, discussions with other judo officials and my interpretation of the current written judo contest rules covering scoring requirements. Since I have strong feelings about this topic, I am writing this paper in the first person.

Based on personal observations of judo contests I have found that depending on the geographical location of the contest, many officials vary in their personal interpretation of scoring requirements when it comes to throwing actions. This is somewhat of a sad commentary, indeed.

The throwing scores of Ippon, Waza Ari, Yuko and Koka will be discussed and include my interpretation of the requirements for each of the scores. Also, where I feel it is necessary, some suggested additions which will help to further clarify scoring requirements will be introduced.

With regard to all scores, I firmly believe that the required elements to achieve any score should be based solely on those conditions which exist at the moment of impact with the mat. Whatever motion that Uke incurs following initial impact should not be considered!


The referee shall announce Ippon when a contestant with control throws the other contestant largely on his back with considerable force and speed.

a) Control

This requirement generally presents no problem and seems to be well understood. My interpretation of control is as follows: As long as the Tori maintains a grip on the Jacket of the Uke up to impact, control has been established. If this assumption on my part is correct, it would make sense for the International Judo Federation (IJF) Refereeing Commission to so state in the rules.

Control is a requirement for the four scores and no partially lacking is allowed for any of the four possible scores. If, for example, the elements of largely on the back and considerable force and speed are evident but control is lost prior to mat impact by the Uke, then there should be no announced score by the referee.

b) Largely on the back

This requirement, for reasons I fail to understand is one where a great disparity exists in its interpretation. I have on many occasions listened to discussions by judo referees stating their different interpretations of what constitutes the definition of largely on the back. Here again is an area where the IJF could and should give an explicit definition of this requirement in the IJF refereeing rules. If this were done, it certainly would greatly alleviate the misunderstanding associated with the interpretation of this scoring requirement.

It is my opinion that the traditional Ukemi side fall truly mirrors the largely on the back meaning as set forth in the rules as part of throwing score requirements. Consider the final body position of an individual after having been thrown correctly in practice in the dojo. With few exceptions (i.e. Yoko Gake, Tomoe Nage etc.) the body position is the same as that of the finish of a side fall!

Because of what I believe to be a gross misinterpretation of the largely on the back requirement for scoring purposes, Ippon awards are being made for what I perceive as unusual terminal body impact conditions. For example, in viewing tapes of world class competition many calls of Ippon are made after the Uke has impacted either directly on his buttocks or right side followed by rolling onto his back! I cannot believe that this is what the IJF Refereeing Commission had in mind when they formulated the largely the largely requirement as part of the scoring requirement.

Some individuals have gone so far as to try to quantify the largely on the back requirement in terms of a percentage of the back contacting the mat at body impact. This is similar to going from the ridiculous to the sublime!

c) Considerable Force and Speed

To be awarded an Ippon considerable force and speed must be evident along with control and largely on the back. These two variables usually present no problem for Ippon calls. However, a serious problem arises when they are considered for determining Waza Ari and Yuko scores.


The referee shall announce Waza Ari when a contestant with control throws the other contestant, but the technique is partially lacking in one (1) of the other three (3) elements necessary for Ippon.

No further discussion is necessary for the elements of control and largely on the back. However, the elements of considerable force and speed will be scrutinized for individual validity as it applies to the awarding of scores.

For the scores of Waza Ari and Yuko the rules state that the referee can for scoring purposes consider that either force or speed can be unilaterally partially lacking. This not possible since physical laws would be violated!

Any student who has studied basic physics knows that force and speed are directly related and must obey Newton’s second law of motion. Simply stated, if force increases, speed increases, or if force decreases, speed decreases. You cannot change one and hold the other constant!!

We will now examine which conditions at mat impact would warrant the call of Waza Ari recognizing that force and speed are mutually dependent.

A throwing action made with control and considerable force and speed but partially lacking in the largely on the back element should be called a Waza Ari. Sounds reasonable enough, but very often the call is Yuko. This erroneous call stems from the belief that a side body impact warrants a Yuko without consideration of the other elements that make up a Waza Ari score.I have observed this type of an officiating error many times! As a matter of fact, this is the one and ONLY way in which a Waza Ari can be awarded for a throwing action. It assumes of course, that you believe in Newton’s second law of motion.


The referee shall announce Yuko when a contestant with control throws the other contestant, but the technique is partially lacking in two (2) of the other three (3) elements necessary for Ippon.

Similar to the case for the call of a Waza Ari, the score of Yuko can only be called for one set of conditions unless one is determined to violate Newton’s law.

If the one contestant throws the other contestant with control and largely on his back but is partially lacking in BOTH considerable force and speed, the required call is Yuko. If one reflects on having viewed these throwing conditions in a judo tournament, I would be willing to wager that the actual call was most likely an IPPON!

Based on numerous observations of tournament play, if a contestant is thrown and impacts on his side body the call is most likely Yuko regardless of the status of the other required throwing elements.


The referee shall announce Koka when a contestant with control throws the other contestant onto one shoulder, his thigh(s), or buttocks with speed and force.

No specific comments regarding Koka calls in tournament play.


The element of largely on the back in many instances is interpreted differently by referees and judges. It would seem appropriate for the IJF to give an explicit definition of this throwing element in the contest rules.

There is absolutely no question that the force and speed element needs to be revised! A possible solution would be to drop force requirement and require only considerable speed. In so doing, the force would exist anyway, and one would still have the best of both worlds.

All the scoring elements should be those required at the moment of body impact. No consideration should be given to post impact. This would apply specifically to the element of largely on the back since in many cases post impact of the body is subject to different orientations. Because of these orientation changes, many final calls are made based on post impact body orientations!

A definition of control should be included in the IJF rules.

In closing, I would like to quote a line from the book ‘Judo for the West’ by G.R. Gleeson. It is the opening line in the Foreword and reads as follows: “A sport that resists change, dies.”

I doubt very much that we would see the demise of Judo if the suggestions made in this article were ignored. I do believe however, if some changes were made it would certainly ease the burden of officiating judo contests.