Tani Otoshi
Tani otoshi (valley drop) — one leg steps behind and between the opponent's legs; the attacker drops backward, pulling the upper body down while the…
Adapted from InGrappling, Tani Otoshi. System Games did not invent this curriculum.
Manage injuries →Position map Connects to 2 positions across 2 relationshipsOpen in the map →12←Enters from
Tani otoshi — valley drop in Japanese — is a sacrifice throw in which the thrower steps one leg behind and between the opponent’s legs, drops backward to the mat while pulling the opponent’s upper body down and across, and uses the stepping leg as a block against the opponent’s near leg to prevent their base from recovering. The combined pulling and blocking motion sweeps the opponent over the stepping leg and to the mat.
In judo, tani otoshi is classified as a ma-sutemi-waza (rear sacrifice technique) — a throw in which the thrower falls backward intentionally, using their own dropping body weight as the throwing force. The sacrifice element is what distinguishes it from standing throws: the thrower goes to the mat with the opponent.
In submission grappling contexts, tani otoshi appears in three primary situations: as a clinch counter when the opponent has a rear body lock or bear hug, as a counter throw when the opponent is completing a throw (going with the throw and redirecting), and as a seated guard sweep variant when the bottom player pulls an approaching opponent forward and down while stepping a leg through to block. All three share the core mechanic — backward drop, upper body pull, leg block — but the entry and grip differ.
INV-13Invariant "Destabilisation precedes control. An opponent who retains structural balance can generate defensive force regardless of the position they are in."
Why it works hereThe kuzushi pull and the blocking leg are paired because each one alone leaves structural balance intact: a pulled torso can be recovered by a back step, and a blocked leg can be braced against without the upper body being committed. Together they remove balance entirely — the centre of mass is dragged behind the base while the base itself cannot reposition. The sacrifice drop only converts to a throw because the opponent has already lost the structural balance that would otherwise let them post and recover during the fall.
See full invariant page → The tani otoshi’s destabilisation comes from the combination of the backward pull and the leg block. The pull at the upper body pulls the opponent’s centre of mass backward and down; the blocking leg removes the base that would absorb that pull. Alone, the pull can be resisted by a strong base — the leg block is what removes that resistance. Alone, the leg block creates no tipping direction — the pull provides it. Both are required, and the destabilisation is complete only when both act at once.
INV-ST01Invariant "Destabilising the opponent requires controlling the secondary leg — the leg that is not the primary base. Moving the secondary leg removes the opponent's ability to rebalance."