An Ippon is determined within three ways, 1) throwing the opponent on thier back, 2) forcing the opponent to submit to an arm-lock or choking maneuver. 3) Pining the opponent to the ground within a specific time, or 4) the opponent forfeits by tapping the mat with their hand or foot.
The rules of judo are a style of time and control, with an Ippon or completion win.
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United States Judo Association - USJA