The green contest area at the centre is a six metres square, surrounded by a one metre red alert area, which in turn gives way to an outside, or safety, zone which is three metres wide. Strips of white and blue tape in the contest area mark the point at which the contestants start their bout. Judoka wear judogi, pants and jacket with a black belt to signify their status. One judoka wears a blue judogi, the other wears a white one. Judoka can win the bout with a throw that immobilises an opponent in a hold for 25 seconds.
Submission brings the same result.
Similarly, a waza-ari is awarded if the hold lasts for 20 seconds, not 25. A yuko is awarded if two elements of a throw are missing or a hold lasts between 15 and 19 seconds. A koka is awarded if three elements of a throw are missing or if a hold lasts between ten and 14 seconds. Yuko and koka can be awarded to one opponent as a penalty to the other opponent for rule infringements. A tally of yuko and koka is kept to break a tie.