Ai-yotsu vs kenka-yotsu

Same-side versus opposite-side grips: two different sports wearing one gi — know which one you are in.

In these systems

Russian / Dagestani Sambo-crossover judo: grip fighting as war, low sacrifice attacks.

11x world, 3x Olympic champion Teddy Riner The heavyweight reign: osoto, uchi-mata and grip dominance measured in decades.

Canon: the Kodokan 100 (68 nage-waza, 32 katame-waza; IJF/Kodokan classification) · Daigo, Kodokan Judo Throwing Techniques · Kashiwazaki