This is a brief introductory guide to judo tournaments for beginners, spectators and parents.
Start of a Contest
Prior to a judo contest (shiai) one contestant is assigned a blue sash to wear in addition to their obi (belt) and/or they will be asked to wear a blue Judogi. After the contestants have bowed and stepped forward, the referee announces hajime (begin) to start the contest.
Scoring a Contest
In Judo competition the objective is to score an ippon (one full point). Once such a score is obtained the competition ends. An ippon can be scored by one of the following methods:
If the time runs out with neither contestant scoring an ippon, then the referee will award the win to the contestant who has the next highest score. For example, a contestant with one waza-ari would win against an opponent who scored 4 yuko.
There should be one or two scoreboards to show the state of play. Because in Judo it is always the highest quality score that wins, the score-board is laid out left to right to show the scores like a number.
Looked at in this way, the score is 10 to 3: white's single waza-ari beats the lesser quality of blue's 3 yuko. The Ippon score is not shown on the scoreboard because there can only be 1 Ippon and scoring it ends the match.
Basic Judo Referee Signals (more)
Ippon (full point): Opponent is thrown on the back with force, or held under control on the mat for 25 seconds.
Waza-ari (near ippon): Throw is not completely successful, or opponent is held under control for at least 20 seconds.
Yuko (almost waza-ari): Throw is partially successful, or opponent is held under control for 15 to 20 seconds.
Osaekomi (mat hold begins): Opponent is held under control on his or her back and the time starts.
Matte (stop): Match is stopped temporarily and the time clock pauses.