Inside Sankaku

Inside sankaku in no-gi: the triangled upgrade of cross ashi (the saddle) — a figure-four around the near leg with the top leg crossing past the far leg. The most locked-down inside heel hook position.

Adapted from InGrappling, Inside Sankaku. System Games did not invent this curriculum.

FamilyLeg EntanglementsLevelAdvancedPerspectiveMutualIntentCounter-offensiveSafetyElevatedHubLeg EntanglementsMapView on graph →This technique has elevated risk. Make sure you've covered the prerequisites before attempting.

Manage injuries →Position map Connects to 4 positions across 3 relationshipsOpen in the map →1234←Enters from

Inside sankaku is the triangled upgrade of cross ashi — the saddle. Where the saddle has both of the attacker’s legs crossed to the same side of the captured leg, inside sankaku closes that cross into a true triangle: the attacker forms a figure-four around the opponent’s near leg, with the top leg crossing all the way past the opponent’s far leg. The distinction is simple and worth holding precisely — if the legs only cross, it is the saddle; once they triangle, it is inside sankaku.

Forming the triangle is what makes the position the most locked-down inside heel hook control in grappling. The figure-four removes slack, fixes the hip line bilaterally, and takes away the small rotations the opponent uses to begin an escape from a looser saddle. This is why it sits at the top of the inside-position hierarchy: the same inside-heel exposure as the saddle, but with the leg configuration sealed.

Elevated RiskInside Sankaku is an elevated risk technique. The inside heel hook from inside sankaku attacks the ACL and medial knee structures through rotation. The triangled configuration seals the saddle's bilateral hip control, removing the small rotations a looser position allows — so the escape window is shorter still. Serious injury can occur within a small number of rotational degrees.

If you are new to this technique: read this section before anything else. Understanding the danger is part of understanding the technique.

The person applying the technique is responsible for releasing immediately.

Communicate before drilling. Know your partner's experience level with this position.

Games

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