International Sumo Federation Regulations Concerning Refereeing
Chapter 1 Regulations on Refereeing
A sumo referee shall be an ISF certified referee, selected by the Organizing Committee.
A team of referees shall consists of a head referee, a gyoji (a referee on the dohyo), and four sub-referees (a total of six referees).
2. The head referee shall take full responsibility for all decisions made pertaining to amatch.
3. The gyoji assumes the leadership of a match from the time the athletes enter the ring (dohyo) to the end of the match when they exit the dohyo.
4. The roles of the sub-referees are to assist the head referee and to ensure that there are no inaccuracies in the decision.
5. The sub-referee in the front shall also function as the timekeeper.
6. The referee manager is responsible for executing all matters pertaining to general affairs in judging including assignment of referees.
With the exception of special rules, the following rules apply to an athlete who is selected the winner of a match.
(l) The athlete who pushes his opponent of the shobu-dawara (rice-bale boundary circle).
(2) The athlete who forces any part of his opponent's body, other than the soles of his feet, to touch the dohyo.
When the opposing athlete completely loses his center of balance, it is not a loss if an athlete touches, slightly before the opposing athlete, in either the inner or outer area of the dohyo with his had.