An ippon in judo is an instant win. You get it in one of three ways: a throw that lands your opponent clearly on their back with force, speed and control, a hold-down kept for 20 seconds, or a submission to an armlock or strangle. The referee raises one arm straight up, palm forward, and the match stops.
It sounds clear-cut. In practice it is the call that sparks the most arguments in the stands, because the line between ippon and waza-ari comes down to a few degrees of shoulder angle.
Where does the word ippon come from?
"Ippon" combines "ichi" (one) with "hon", a Japanese counter used for long objects. It is usually translated as "one point" or "one full point". The same word means a winning strike in kendo. It also appears in ippon-seoi-nage (one-arm shoulder throw), which has nothing to do with the score.
The idea comes from real fighting: a perfect throw onto hard ground would have left the opponent unable to carry on. Sport judo kept that logic. One technique is enough.
The four criteria of an ippon throw
When tori (the thrower) throws uke (the one being thrown), the referee checks four things at once.
- Back: uke has to land largely on the back. A landing on one side, one shoulder alone or the backside is not enough. The upper back alone now scores yuko.
- Force: the throw needs impact. An opponent placed down slowly does not give ippon, even if they end up flat.
- Speed: it goes with force. The movement must be continuous, with no stop halfway.
- Control: tori keeps control of uke all the way down, usually through the pulling hand (hikite). If tori lets go and falls randomly, the referee takes a criterion away.
One special case is the rolling fall. The IJF accepts ippon on a roll as long as the fall does not stop and uke rolls clearly across the back from one side to the other. If the roll stops on a shoulder, it is waza-ari at best.
The throw also has to be a technique recognized by the Kodokan, or a recognizable variation. A plain shove that knocks your opponent over scores nothing. One more reason to drill the gokyo techniques properly.
Ippon on the ground: hold-downs and submissions
On the ground, the referee calls "osaekomi" when tori controls uke on their back with a recognized hold-down (kesa, shiho or ura). The clock runs. At 20 seconds it is ippon. If uke escapes earlier, the referee calls "toketa" and the score matches the time elapsed.
Submission is the other route. Uke taps twice or more on the mat, on tori or on themselves, or says "maitta" (I give up), against an elbow lock or a strangle. A player who passes out from a strangle also loses by ippon. The legal ground techniques are covered in our katame-waza article, for example juji-gatame (cross armlock) for armlocks.
The referee's signal
For ippon, the referee raises one straight arm above the head, palm forward, and calls "ippon". They hold it for a few seconds, then send the players back to their marks. For waza-ari, the arm goes out to the side at shoulder height. The rest of the signals are on our page about judo referee commands.
A call can be corrected by the judges on video. You then see the referee wave a hand above the head to cancel, then give the right score. That is not weakness. The video is there for exactly that.
Ippons that look real but are not
These are the situations coaches argue about most from the side of the mat.
- Uke lands on the back but tori threw in slow motion, in two stages: waza-ari.
- Uke lands on the side and then rolls onto the back: the first contact is judged, so waza-ari or yuko.
- Uke touches down first with both knees or the stomach before tipping over: no score at all.
- Both players fall together and nobody can tell who threw: no score.
On the other hand, a player who bridges to avoid landing on the back hands the ippon to the opponent. The rule is strict because bridging puts the neck at risk. Kids are taught to roll or land on the stomach rather than fight the fall with the head.
Ippon or waza-ari: how to tell
For the full picture on waza-ari, read our waza-ari page. The short version: a waza-ari is an ippon that is missing something. One weak criterion, an incomplete landing or a hold-down that was too short. Two waza-ari add up to ippon.
The overall framework is collected in our guide to judo rules.
How to chase ippon in training
The players who score ippon are not always the strongest. They are the ones who finish their techniques. In nage-komi, do not let go of the sleeve the moment uke leaves the ground: pull all the way down, follow the fall and keep uke's head under control. That last quarter of a second turns a waza-ari into an ippon. A simple drill: sets of ten throws where only the finish counts. You will see the difference within a few weeks.