Octopus Kosoto Sweep

What This Is

The octopus kosoto sweep applies the judo foot technique kosoto gake — small outside reap — from octopus guard. Octopus guard is the position where the bottom player has an arm wrapped around the passer’s back (the “octopus arm”) and an underhook on the same side, creating a body lock that constrains the passer’s upper body movement and prevents them from posting or straightening up freely.

Kosoto gake reaps the ankle from outside: the attacking leg inserts between the passer’s legs and contacts the far ankle, then reaps outward and upward to remove that base point. In the octopus context, the body lock arm provides the coordinating pull — pulling the passer’s shoulder back and upward at the same moment the ankle is reaped removes the passer’s ability to step and recover. The passer is pulled backward by the upper body while their far base point is simultaneously removed, forcing a backward fall.

This is not a strength-based throw. The mechanical logic is: unload the far leg first with the upper body pull, then reap the ankle once it has minimal weight on it. Trying to reap a loaded ankle is ineffective — the sequence of pull then reap is the technique.

The Invariable in Action

The octopus arm (wrapped around the passer’s back) and the underhook together function as a full upper body lock — but the critical connection is the underhook, which reaches the inside of the passer’s arm and controls the near elbow. When the bottom player’s underhook drives upward into the passer’s armpit, it displaces the passer’s weight to the far side and makes it difficult for them to drop that elbow to base. This elbow displacement is what sets up the backward pull that loads the kosoto reap.

The kosoto reap targets the passer’s far ankle specifically because it is the base point furthest from the body lock’s control. When the bottom player’s body lock pulls the upper body backward, the passer’s natural response is to step the far foot back to widen their base and recover — the kosoto reap intercepts this step and removes the base point before it can be used. The reap creates an offensive opportunity by removing the post the passer is trying to establish.

The upper body pull with the octopus arm is the load for the kosoto reap. The pull shifts the passer’s weight backward onto the far leg, which is the leg being reaped — this is the load. A heavily weighted ankle is actually easier to reap than an unloaded one in terms of commitment (the passer cannot simply lift it), but the reap must follow the pull quickly enough that the passer has not had time to step around it. Pull to load, reap to finish — the load and the reap must be closely sequenced.

The octopus guard body lock means the passer is already being controlled frontally. The kosoto reap introduces a backward direction change — the passer is pulled backward while their ankle is swept forward (out from under them). This front-to-back direction change is structurally disruptive because the passer’s defensive response to the octopus guard is typically forward-resistance (resisting being pulled forward) — the backward pull changes the direction they must resist and the ankle reap catches them in that transition.

Setup and Entry

Octopus guard establishment

The kosoto sweep requires a solid octopus guard to begin. From a guard position where the passer has come close — typically mid-pass attempt or when they are driving into the bottom player — the bottom player threads one arm around the passer’s back (reaching past the hip or around the waist) and establishes an underhook on the same side. The arm around the back grips the passer’s far side; the underhook arm threads under the near arm.

The body lock must be tight before the sweep is attempted. If the passer can straighten up, they will simply step back and the lock is lost. The bottom player keeps their elbow tight and their body connected to the passer’s hip — not reaching and floating.

Inserting the reaping leg

From the octopus position, the bottom player feeds one leg between the passer’s legs — from the inside — to reach the far ankle. The leg travels along the mat or just above it, with the foot contacting the passer’s far ankle on the outside. This is the kosoto contact point: outside of the far ankle, foot hooking behind or beside it. The reaping leg should not be hurried in — it should travel with control to make solid contact before the reap begins.

Execution

With the kosoto contact established and the octopus body lock secured, the sweep executes in a coordinated two-part motion.

Part one: the octopus arm pulls the passer’s shoulder backward and upward. This is not a lateral pull — it is directly backward, as if pulling the passer’s shoulder toward the floor behind them. The underhook arm assists by driving upward into the passer’s armpit, which elevates their shoulder on that side and amplifies the backward tipping effect. Together, these create the backward weight shift that loads the far ankle.

Part two: as the pull begins to load the far ankle, the reaping leg scoops outward — from the inside of the ankle sweeping outward and forward. The reap removes the ankle from its base position. The motion is comparable to a sweeping kick: contact with the inside of the ankle, reap outward in a short arc. The foot does not need to travel far — a few inches of reap is sufficient once the upper body pull has created the backward lean.

The sequencing: pull, then reap. Not simultaneously (the ankle must be loaded first), and not reap then pull (the ankle reap without upper body load has no force to work against). The window between pull and reap is very short — the pull loads the leg and the reap follows immediately while the passer is still overbalanced.

The passer falls backward. As they fall, the bottom player maintains the body lock and follows them to the floor, arriving in a top position with the body lock intact — often directly into a front headlock or back-take position depending on the fall angle.

Common Errors — and Why They Fail

Drilling Notes

Ecological approach

Flow roll from octopus guard where the top player is actively trying to extract the body lock and stand back up. Bottom player’s constraint: the sweep must use the kosoto ankle reap. Top player responds naturally — they will often step the far foot back, which is exactly the timing the sweep targets. Switch roles every two minutes. Note how often the passer’s natural defensive step back creates the window.

Systematic approach

Drill in three isolated phases. Phase one: octopus guard establishment only — practice getting the arm around the back and the underhook without the partner cooperating on the lock. Ten entries each side. Phase two: with the lock established, practice only the upper body pull — pull the shoulder back and feel the partner’s weight shift to the far leg. No reap. Ten times, focusing on the weight transfer. Phase three: from the weight transfer, add the ankle reap. Ten times at slow speed, monitoring the sequence. Link the phases only when each feels natural.

Ability Level Guidance

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