01 / AT A GLANCE
O-soto-gaeshi: the defining action
O-soto-gaeshi counters an o-soto-gari attack with an outer reaping action of its own. The opportunity exists while the defender can still organise posture and reverse the controlling relationship; it is not a late contest of two falling legs.
Name and scope: O-soto-gaeshi (大外返), commonly rendered as large outer reap counter, belongs to Ashi-waza. Searches for “o soto gaeshi” and the hyphenated spelling refer to the same official technique here. An informal nickname should be checked against the actual action before being treated as a separate technique.
Position convention: Uke attacks with right o-soto-gari. Tori counters with the right leg after preserving a grounded stance and taking control of the shoulder direction. The same-side leg relationship should be rehearsed slowly before resistance increases. Tori means the person performing the technique and uke the receiving partner. When reviewing a mirrored camera image, identify each person’s own sides first. Reverse the whole relationship for a left-sided lesson rather than changing one limb while preserving incompatible directions elsewhere.
The intended reader can already practise under supervision and wants to connect demonstration, diagnosis and decision-making. For o-soto-gaeshi, the central question is: win a usable shoulder-and-support relationship before applying the return reap. Beginners can study the shape with a coach; applying it against variable resistance requires the additional recognition and control work below. The article does not assign a universal belt level or promise that one body type will succeed automatically.
02 / WATCH THE TECHNIQUE
Official demonstration and a second viewing reference
Open this video on YouTube if the player is unavailable.
Open this video on YouTube if the player is unavailable.
Observe the upper-body contest before comparing the reaping legs. The moment the defender gains a usable base is more informative than the final image of one leg behind another.
Official reference: Kodokan. Second demonstration: Efficient Judo. Open the publisher links if either embedded player is unavailable.
A practical viewing question is: “Have I changed who controls the shoulder line, or am I only adding my leg to the opponent’s successful attack?” Compare that question across the official and second reference. Differences in speed, partner stance or grip route may explain different appearances. Do not combine isolated details from incompatible versions into one repetition. No timestamps or claims about unseen scoring sequences are supplied here.
03 / WHEN TO USE IT
Recognise an opening and recognise its absence
A usable starting relationship
The original attacker approaches outside but has not carried tori’s shoulder line beyond recovery. Tori can keep or regain an upright base and bring the attacker’s trunk into the countering outer-reap direction.
Against right o-soto-gari, tori’s threatened right leg is also the leg used for the return outer reap in this reference. That fact does not eliminate the need for a supporting left foot and a changed shoulder relationship. Before adding the return leg action, rehearse the close outside approach with both feet available. Tori should show where the support remains and how uke’s torso is redirected into the countering rear corner.
When the same shape is not an opening
Tori is already falling backward with the attacked leg lifted and the shoulders controlled. Swinging the free leg in that state does not reliably restore the counter position.
When uke controls the shoulder line beyond tori’s base, a visible opening behind the attacking leg may already be unusable. The return reap then becomes an effort made while falling. Use a slow comparison between an early outside approach and a completed controlled reap. Tori counters only the early relationship that preserves support. The later repetition is for ukemi, allowing both partners to learn the boundary without an uncontrolled one-leg contest.
Movement to invite or read
Use a slow outside approach and stop before the original reap completes. Tori rehearses the upper-body reversal, then gradually links it to the countering leg while the stance remains stable. In an opposite-lead or unfamiliar grip arrangement, have the coach map the relevant limbs again. The fixed convention in this article provides a reference for comparison; it does not guarantee that the same approach distance survives every stance.
04 / HOW IT WORKS
Connect the grips, support and finishing action
Hands and upper-body connection
The hands and chest connection reverse the upper-body advantage before the countering reap. Contain uke’s near shoulder and direct the torso into the rear corner appropriate to the counter, rather than letting the two legs fight under an unchanged shoulder position.
Feet, hips and available support
Maintain a supporting foot under the body and position the right leg for the countering outer reap. The support must allow the torso to act with the leg; reaching the countering leg from a collapsing stance removes that coordination.
Complete the action under control
Reap as the hands and body carry uke backward through the newly established direction. Keep the action continuous and controlled, then guide the landing instead of dropping both bodies into a tangled leg exchange.
Study the relationship beneath the visible shape
The most tempting error is to answer the opponent’s leg with another leg movement while leaving the upper-body contest unchanged. If uke still controls the shoulder line and tori’s support is disappearing, a return reap has little foundation. Start from an early outside approach and practise changing the shoulder direction with both feet available. Only when tori can preserve a stable base should the countering leg be added.
This does not mean stopping the action into a rigid strength test. The slow pause is a learning device that reveals whether the position is viable. As movement returns, the posture change and reap must connect. The practical cue is the attacker’s approach and shoulder commitment, not the moment tori is already falling backward. A counter learned only from a perfectly frozen entry may arrive too late in randori.
05 / KEY POINTS
Four cues with observable checks
Keep the defining mechanism visible
Win a usable shoulder-and-support relationship before applying the return reap. Ask the observer to describe that action before commenting on power. If a repetition succeeds through a different mechanism, record what actually happened. A fall or escape can be useful without proving that the intended o-soto-gaeshi relationship improved.
Verify the position before adding commitment
Before finishing, tori should be able to show a grounded support and a changed shoulder direction. If only the legs have changed, the counter may still belong to the original attacker. Use this as a brief checkpoint in cooperative practice, then remove the pause as coordination improves. The checkpoint is not a recommendation to freeze during a live exchange; it is a way to identify the relationship that must survive movement.
Preserve the correct stopping decision
Use a coach-arranged unavailable position to check your decision before adding resistance to o-soto-gaeshi. The precise release or reception boundary is described in the defence section below. Otherwise, a partner who always supplies the ideal opening can teach commitment without teaching selection. A correct reset belongs in the practice record alongside a controlled completion.
Make the result lead to a next position
The close outer-leg exchange can leave legs entangled after the fall. Maintain upper-body guidance, then free the lower-body relationship before placing heavy chest pressure for a hold. The observer should describe the actual ending, not the intended ending. That description determines whether the next task belongs to finishing, stabilising on top or recovering underneath.
06 / PROBLEMS & ADJUSTMENTS
Diagnose the earliest cause before changing force
Both partners hop on one foot without either controlling the fall.
Tori may have answered the leg action before changing the upper-body relationship. The supporting foot may be too far behind the shoulders to carry the counter. These are competing explanations to investigate, not a diagnosis made from the result alone. The next repetition should reveal which relationship fails first.
Test: Pause the original attack before the reap and practise only the countering posture and hand direction. Let uke offer light resistance. Add a small leg action only after the shoulder line can be changed without hopping. Adjustment: Start recognition earlier and organise the supporting stance before increasing the countering reap. Keep the other conditions as similar as practical for the comparison. An improvement in the relevant connection is more informative than one accidental completion after several unrelated changes.
The drill turns into a strength contest
If the drill becomes a strength contest, reduce resistance and give uke a specific entry speed. Repeated uncontrolled hopping makes the critical timing less visible and can leave either partner falling onto a trapped leg. For o-soto-gaeshi, partner feedback should identify where the action was felt and when it changed. Combine that report with the observer’s view; an outside camera and an inside contact sensation provide different pieces of evidence.
Trace hops back to the first loss of stance
Count uncontrolled hops during review, but investigate their cause rather than treating hopping as the sole mistake. Tori may hop because the support foot began too far away, because the upper body leaned backward or because the counter started after the original reap had already removed the base. The video should be read backward to the first loss of stance. Correcting that moment is more useful than instructing the learner to keep the foot still during an already unstable exchange.
The partner should offer a credible outside approach without trying to win a prolonged one-leg contest. Once either person loses control of the landing, reset. This preserves the ability to study the early counter relationship. A series of desperate reversals may look competitive but gives poor information about whether the intended mechanism was available.
07 / SETUPS & COMBINATIONS
Make the next action depend on a response
First route: starting position, response and continuation
Uke approaches right o-soto-gari from close grips. Tori establishes the countering shoulder direction and right-leg reap only while the base remains available. If uke withdraws the attacking leg before that relationship forms, tori faces and resets rather than chasing a leg that has gone.
In the entry drill, uke approaches with right o-soto-gari and either commits the upper body or retracts before the reap. Tori attempts the reversal only while a support and shoulder-direction change remain available. The observer should watch the torso before the legs. If both partners begin hopping without a clear controlling direction, reset immediately and return to the earlier posture phase rather than continuing until one person happens to fall.
Second route: recovery or change of direction
When the original attack is prevented but the counter is unavailable, recover both feet and observe uke’s next step. A forward attack can follow an upright recovery, but the choice must be made from the restored stance rather than from a hanging one-leg position.
After preventing the attack without obtaining the counter, tori replaces the right foot and restores facing posture. Uke’s next recovery may invite a forward throw, but only if the grips and distance support it. A continuing hopping exchange is not a stable starting point for that new attack. End the first sequence clearly, then use the next step as the trigger. This keeps the second action from hiding an unresolved loss of base.
08 / DEFENCES & COUNTERS
Separate prevention, recovery and a counter opportunity
The original attacker should avoid reaching the leg ahead of an unsupported torso. The defender’s prevention is earlier posture and angle control; a counter is a further option, not a requirement for every successful defence.
Stop boundary: Receive the original throw when the shoulders are already committed backward and the support is lost. Do not wrench the knee or throw the head backward in an attempt to keep the return reap alive. The receiving partner must retain an agreed ukemi response when the original attack has succeeded. Do not replace reception with a desperate straight-arm post or a joint-twisting rescue.
The original attacker can prevent the reversal by keeping the torso and supporting step connected to the reap instead of presenting a reaching leg first. Let uke vary that coordination gently. Tori should identify when the upper-body relationship can actually be changed. If the shoulder line remains controlled by uke, ordinary defence or reception may be the correct outcome. Adding a leg behind uke is not enough to establish that the counter has taken over.
09 / GROUND TRANSITIONS
Read the position after the main action
If tori lands on top, settle the hips and shoulders before moving into kesa-gatame or another side hold. If both partners roll, identify the actual top position and trapped legs rather than assuming the countering intention determines control.
A close return reap may leave one of tori’s legs caught underneath or between uke’s legs. First keep the torso stable and free the unnecessary standing contact, then choose the hold. If both partners roll, identify which shoulders and hips are actually controlled before applying pressure. The intention to counter does not guarantee a top arrival. A practice record should distinguish a controlled return throw from a scramble that happened after both bases disappeared.
A completed throw and an established hold are separate outcomes. A controlled landing can still require leg clearance or shoulder repositioning before useful top control exists. Compare the actual o-soto-gaeshi ending with the planned one, and practise the common arrival independently if it repeatedly becomes the weak part of the sequence.
10 / PRACTICE PROGRESSION
Progress from a clear shape to a real choice
Stage one: make the reference repeatable
Use the stated o-soto-gaeshi convention with a cooperative partner. Begin slowly enough to identify the grip and support roles, and stop before completing an action that has lost its defining connection. Progress when both partners and the observer can describe the same relationship without guessing. Repetition count alone does not establish readiness.
Stage two: introduce the movement cue
Revisit the specific moving relationship described under “When to use it” for o-soto-gaeshi. First keep its direction predictable, then vary its timing while preserving the same grips and side convention. Keep resistance modest while the cue changes. If the reference shape disappears on every moving attempt, reduce the step or escape amplitude and preserve the correct direction rather than forcing a finish.
Stage three: require a decision
Uke alternates a committed outside approach and an early withdrawal. Tori counters only the connected approach and keeps both feet available when the attack disappears. A useful round includes a correct continuation and a correct decision not to continue. Record both. When these choices remain clear, increase unpredictability before increasing force, with the coach deciding what the pair can control.
Stage four: constrain the exchange, then broaden it
A timing ladder can use an early approach, a close but not completed reap and a controlled completed throw. Tori identifies which states still permit an independent base. The coach decides when a counter can be added. Reception remains an intentional part of the exercise, not a failure to be eliminated at any cost.
When adding a continuation after defence, require both feet to recover before the new attack begins. This separates a useful second action from a blind continuation of the leg contest. In the practice log, record correct resets and received throws alongside completed counters. An improvement may appear as fewer late attempts before it appears as more successful throws, and that is meaningful progress toward a controllable technique.
11 / COMPETITION EXAMPLE
A named official replay selection to study
Verified selection: Anna-Maria WAGNER vs Patricia SAMPAIO — European Judo Championships Seniors Individuals 2024. The IJF technique library page includes this contest in its O-soto-gaeshi technique-tagged replay data. The listing verifies the named pairing, event and technique tag. The listing credits the tagged action to Anna-Maria Wagner. It does not by itself establish the final score, a precise timestamp or a complete tactical account.
Use the selection to investigate one question: “Have I changed who controls the shoulder line, or am I only adding my leg to the opponent’s successful attack?” Before the tagged action, identify the grips and movement that made the situation possible. During the action, compare the defining connection with the official demonstration. Afterward, identify recovery and position. If the player or angle does not show one of those phases, leave that part of the observation blank rather than inferring it from the tag.
A useful competition note for o-soto-gaeshi separates three things: what the official listing states, what you can actually see in playback and what you propose to test in practice. This article confirms the first and supplies prompts for the other two. It does not present an unviewed sequence as a frame-by-frame analysis, nor treat historical footage as certification under current event rules.
12 / VARIATIONS & COMPARISONS
Keep neighbouring techniques and variants distinct
O-soto-gari describes the major outer reap itself; o-soto-gaeshi identifies its countering use against the named attack. Ko-soto-gari targets a different smaller outside reap relationship and should not be substituted merely because both throws go backward.
O-soto-gari explains the reaping mechanism used in the return action; o-soto-gaeshi identifies its countering relationship against the named attack. Ko-soto-gari uses a different outside contact and should not be substituted solely because the opponent falls backward. Kesa-gatame concerns the subsequent ground position, which must be established after the legs and shoulders have settled.
13 / YOUR NEXT PRACTICE
One task, one observation and one next decision
Task: Find five early o-soto entries where the shoulder direction can be changed while a grounded support remains.
Record: Track posture reversal before leg action, number of uncontrolled hops and whether the counter was abandoned appropriately when late. Use the practice record template or the practice tools described in Judo AI. Include the starting stance, partner response and the single adjustment tested, so the observation remains interpretable at the next session.
Illustrative example — not measured user data: An illustrative round contains six entries: two controlled counters, two safe resets and two received throws. The useful improvement is reducing late counter attempts, even if the number of throws remains two.
Coach question: “Have I changed who controls the shoulder line, or am I only adding my leg to the opponent’s successful attack?” Bring one clear success and one clear failure if recording is permitted. For o-soto-gaeshi, choose the next drill from the earliest difference between them. Keep an adjustment that improves the intended connection across several comparable attempts; revise it when the predicted change does not appear. The purpose of the record is a better next decision, not a decorative count of repetitions.
14 / SOURCES & REVIEW
Sources, authorship and review
Kodokan official technique names establish the name and category. The IJF O-soto-gaeshi definition and video library and linked Kodokan demonstration are the primary technical references. The second video above is credited separately. The official replay listing in section 11 verifies the named contest and technique tag, not an unviewed score or every coaching proposal here.
By Judo AI · Editorial review: October 9, 2026. Definitions, source identity, article consistency and links have been checked. Practice tasks and diagnostic questions are editorial proposals to discuss with your coach, not a validated training protocol. Named technical-coach approval is still pending. Video identities were verified; complete playback and every contest detail have not been independently analysed.
Rules and scope: this is a supervised judo study guide, not a current refereeing manual. Historical footage does not establish current rule permissions. Ask your coach to check the applicable age group and event rules before using grip variations or submissions in shiai; this draft does not certify their legality. Stop a practice action when your partner taps, asks to stop or reports pain.
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