What must happen to the butterfly hook before you can safely initiate the knee slice motion?

The butterfly hook must be completely neutralized through hip pressure, shin pin, or direct hand control before beginning the slice. You verify neutralization by testing whether the bottom player can generate meaningful upward lift through the hooked leg. If any elevation potential remains, the hook will catch your forward momentum during the slice and convert it into a sweep. Treat hook neutralization as a mandatory prerequisite that must be confirmed before advancing to the slicing phase.

Your opponent elevates with the butterfly hook as you begin the knee slice—how do you adjust?

Immediately abort the slice and address the hook. Drop your hips low and sprawl your weight back onto the butterfly hook side to kill the elevation. Post your far hand wide on the mat to create a base point against the sweep direction. If the elevation has significant momentum, circle toward the non-butterfly side while maintaining shoulder pressure to redirect their sweeping force. Only reattempt the slice after re-establishing both upper body control and hook neutralization.

What is the correct trajectory of the slicing knee during execution?

The knee travels diagonally across the bottom player's thigh line, moving from inside to outside while angling toward their far hip. The power comes from hip extension driving forward and down, not from pushing the knee independently. The shin maintains constant contact with the bottom player's inner thigh throughout the slice, scraping across rather than lifting away. This diagonal path with continuous contact prevents the bottom player from inserting frames or recovering guard during the slicing motion.

The bottom player inserts a knee shield as you begin the slice—what options do you have?

You have three primary options when a knee shield appears. First, transition to a smash pass by dropping your hip weight directly onto the knee shield to flatten it and drive through with heavy pressure. Second, backstep by reversing your slicing leg behind their knee shield to attack from a new angle on the opposite side. Third, maintain crossface pressure and work to strip the knee shield by pushing their knee toward the mat with your hand before re-initiating the slice. Forcing the knee slice through an established knee shield is the least effective option.

What grip or control must be established on the far side before committing to the slice?

A crossface driving your shoulder into the bottom player's jaw to turn their head away from the passing direction is the primary control. The crossface prevents them from following your movement, sitting up into sweep posture, or turning to insert defensive frames. Alternatively, an underhook on the butterfly hook side that controls their far shoulder provides similar upper body dominance. Without either of these controls, the bottom player retains enough mobility to counter the slice through head following, underhook establishment, or posture recovery.

Where should your weight be distributed during the slicing motion?

Weight should be distributed forward through your chest and shoulders into the bottom player's torso, creating constant chest-to-chest pressure. Your hips drive the slice forward and down while remaining as low as possible to prevent space creation. The free leg carries minimal weight but posts wide for base stability. Avoid sitting back on your heels or rising up above the bottom player—both errors create space that enables defensive reactions. Think of your body weight flowing through your chest onto their chest, with the hip as the engine driving everything forward.

Knee Slice from Butterfly Half Attacker | BJJ Technique Guide

Executing the knee slice from butterfly half guard top requires a disciplined sequential approach that distinguishes it from a standard knee slice. The primary challenge is the butterfly hook, which acts as an active defensive mechanism capable of elevating and sweeping you if you attempt to slice without first neutralizing it. The pass demands that you solve three problems in order: kill the butterfly hook through hip pressure or direct control, establish dominant upper body position through crossface or underhook, and then execute the slicing motion with committed forward drive while maintaining chest connection. Rushing any step exposes you to sweeps from the butterfly hook or reguarding through the half guard trap. The successful passer treats this as a methodical progression rather than a single explosive movement, reading the bottom player’s defensive adjustments at each stage and adapting the passing angle accordingly.

From Position: Butterfly Half Guard (Top)

Key Attacking Principles

What are the key principles for executing Knee Slice from Butterfly Half?

Kill the butterfly hook before initiating the knee slice—attempting to slice over an active hook is the most common cause of failure and sweep
Establish dominant upper body control through crossface or underhook before committing lower body to the slicing motion
Maintain chest-to-chest connection throughout the slice to prevent the bottom player from inserting frames or recovering guard
Drive the slicing knee diagonally across the thigh line using hip pressure, not just leg movement—the hip drives the knee
Post the free leg wide with toes gripping the mat for base stability against sweep attempts during the transition
Use sequential weight shifting rather than jumping into the pass—transfer pressure from butterfly hook control to the slicing motion progressively
Arrive with your upper body first and let the lower body follow—head and shoulders establish side control before the legs finish clearing

Prerequisites

What do you need before attempting Knee Slice from Butterfly Half?

Butterfly hook must be neutralized or controlled through hip pressure, shin pin, or direct hand control before beginning the slice
Crossface or underhook established on the far side to prevent the bottom player from following your passing motion
Half guard entanglement identified and weakened through preliminary pressure or angle adjustment
Free leg posted wide with stable base on the mat to resist sweep attempts during the passing transition
Bottom player’s upright posture broken or at minimum compromised so they cannot load the butterfly hook with full elevation power

Execution Steps

How do you execute Knee Slice from Butterfly Half step by step?

Establish Upper Body Control: From butterfly half guard top, fight to establish a crossface by driving your shoulder into the bottom player’s jaw and turning their head away from the passing direction. Alternatively, secure an underhook on the butterfly hook side by threading your arm under their armpit. This upper body control must be in place before any lower body passing mechanics begin, as it prevents the bottom player from sitting up into a strong sweeping posture and limits their ability to follow your movement during the slice.
Neutralize the Butterfly Hook: With upper body control established, address the butterfly hook by dropping your hip weight onto the hook side, collapsing the space the bottom player needs for elevation. Drive your hips low and forward, using your body weight to flatten their butterfly hook foot to the mat. You can reinforce this by placing your shin across their hook foot or using your free hand to push their knee down toward the mat. The hook is neutralized when the bottom player can no longer generate meaningful upward lift through their hooked leg.
Position the Slicing Knee: With the butterfly hook controlled, angle your trapped leg so that the knee points diagonally across the bottom player’s body toward their far hip. Your knee should be positioned at the apex of their thigh line, ready to begin the slicing trajectory. Keep your shin tight against their inner thigh to prevent them from recovering the butterfly hook or switching to a knee shield frame during this transition. Your weight should be distributed forward through your chest and shoulders, not sitting back on your heels.
Drive the Knee Across: Initiate the slice by driving your hip forward and down while your knee travels diagonally across the bottom player’s thigh. The power comes from hip extension, not from pushing with the knee alone. Simultaneously intensify your crossface pressure to pin their shoulders to the mat and prevent them from turning into you or recovering guard. Your free leg posts wide and drives forward to provide the engine for the slicing motion. Maintain constant chest-to-chest pressure throughout this phase to prevent any space from opening.
Clear the Half Guard Entanglement: As your knee crosses the thigh line, the bottom player’s half guard grip will weaken. Use the momentum of the slice to free your trapped leg by windshield-wipering your foot out of their leg entanglement. Do not pull your foot straight back, as this creates space they can exploit for reguarding. Instead, circle your foot toward the mat on the far side while maintaining forward hip pressure. Your shin should scrape across their thigh as it clears, keeping constant contact rather than lifting away.
Establish Side Control Frames: As your leg clears the entanglement, immediately establish side control grips by sliding your crossface arm deeper under their head and placing your far arm either in an underhook position or controlling their near hip. Your chest should already be connected to their chest from the slicing motion. Spread your legs wide with toes on the mat to create a stable base. Drop your hip weight onto their torso to prevent any bridge or hip escape attempts during the consolidation.
Consolidate Side Control: Complete the pass by settling your full weight into side control position. Adjust your hip placement so your near hip is blocking their ability to turn into you, and your far hip is low to prevent them from inserting a knee. Tighten your crossface to control their head position and limit their defensive movement. Walk your feet toward their head slightly to angle your body perpendicular to theirs, maximizing pressure distribution. The pass is complete when you have stable chest-to-chest connection with controlled head position and no remaining leg entanglement.

Possible Outcomes

Result	Position	Probability
Success	Side Control	50%
Failure	Half Guard	20%
Failure	Butterfly Half Guard	15%
Counter	Half Guard	15%

Opponent Counters

How might your opponent counter Knee Slice from Butterfly Half?

Bottom player elevates with butterfly hook during slice initiation (Effectiveness: High) - Your Response: Immediately drop hips low and sprawl weight back onto the hook to kill the elevation. If the sweep is already in motion, post your far hand wide and circle to the non-butterfly side to redirect their momentum. Re-establish upper body control before reattempting the slice. → Leads to Butterfly Half Guard
Bottom player hip escapes and inserts knee shield frame (Effectiveness: Medium) - Your Response: Transition to a smash pass by dropping your weight onto the knee shield and driving it flat. Alternatively, backstep around the knee shield by reversing direction and stepping your free leg behind their knee shield to enter from a new angle. Do not try to force the knee slice through a fully established knee shield. → Leads to Half Guard
Bottom player secures underhook and drives to dogfight position (Effectiveness: High) - Your Response: Immediately whizzer the underhook arm by threading your arm over their bicep and clamping down with your elbow. Drive your weight onto their shoulder through the whizzer to flatten them back to the mat. If they achieve full dogfight, disengage the knee slice and re-establish top position through crossface pressure before reattempting. → Leads to Half Guard
Bottom player dives underneath to deep half guard (Effectiveness: Medium) - Your Response: Immediately sprawl your hips back to prevent them from getting fully underneath you. Control their far shoulder with a whizzer or crossface and work to flatten them by driving your hip into their face side. If they achieve deep half, transition to the deep half guard passing sequence rather than forcing the knee slice from a compromised angle. → Leads to Butterfly Half Guard
Bottom player grabs your slicing leg ankle and redirects your knee path (Effectiveness: Low) - Your Response: Strip the ankle grip by circling your foot away from their hand while maintaining forward hip drive. The forward pressure of the slice combined with your upper body control makes ankle grips alone insufficient to stop the pass. If they persist, use your free hand to break the grip and immediately resume the slicing motion before they can establish a stronger frame. → Leads to Half Guard

Common Attacking Mistakes

What mistakes should you avoid when executing Knee Slice from Butterfly Half?

1. Attempting the knee slice before neutralizing the butterfly hook

Consequence: The active butterfly hook catches your forward momentum and redirects it into a sweep, sending you over to the side or directly onto your back. The bottom player uses your own commitment to the slice as the engine for their sweep completion.
Correction: Always address the butterfly hook first through hip pressure, shin pin, or direct hand control. Verify the hook is dead by testing for upward lift before initiating any slicing motion. Treat hook neutralization as a mandatory prerequisite, not an optional step.

2. Rising up high to generate slicing power instead of staying low with chest connection

Consequence: Creates space between your chest and the bottom player’s torso, allowing them to insert frames, recover butterfly hook, transition to knee shield, or sit up into a sweeping posture. The space you create becomes the weapon used against you.
Correction: Generate slicing power through hip drive and forward pressure, not by rising up. Your chest should remain glued to their chest throughout the entire slicing motion. Think of sliding your body forward rather than lifting up and cutting down.

3. Neglecting the crossface and relying solely on the knee slice motion

Consequence: Without crossface control, the bottom player can turn into you, follow your passing direction, and either reguard or come up to a dogfight position. The pass becomes a scramble rather than a controlled progression.
Correction: Establish and maintain crossface throughout the entire pass. The crossface pins their head and prevents them from turning or following. Even if your knee slice is technically perfect, without head control the bottom player retains too many defensive options.

4. Rushing the pass as a single explosive movement rather than a sequential progression

Consequence: Skipping steps creates windows where the bottom player can execute sweeps, insert frames, or transition to defensive guards. The explosive approach works against beginners but consistently fails against trained guard players who exploit gaps in your passing sequence.
Correction: Treat the pass as three distinct phases: upper body control, hook neutralization, knee slice execution. Only advance to the next phase when the current one is secured. Methodical progression is slower but dramatically more reliable than explosive attempts.

5. Pulling the trapped foot straight backward during leg extraction instead of windshield-wipering

Consequence: Pulling straight back creates space between your hip and their body, which the bottom player exploits to reguard with a knee shield, recover full butterfly half guard, or insert frames that stall the pass. The backward pull also compromises your base momentarily.
Correction: Windshield-wiper your foot by circling it toward the mat on the far side while maintaining constant forward hip pressure. The foot traces an arc rather than a straight line, keeping continuous contact with their leg and preventing space from opening during extraction.

6. Narrow base with the free leg during the slicing motion

Consequence: Without a wide base, any lateral sweep attempt from the bottom player has a high probability of success because your center of gravity is unstable. Even minor off-balancing from the remaining butterfly hook or a hip bump can topple you.
Correction: Post your free leg wide with toes gripping the mat, creating a stable triangle base with your slicing knee and posted foot. The wider the base, the more lateral force you can absorb during the transition. Adjust base width continuously as you progress through the slice.

7. Allowing the bottom player to re-establish grips after initially breaking their structure

Consequence: The bottom player recovers offensive potential through grips, underhook, or collar tie, forcing you to restart the passing sequence from the beginning while having expended energy on the failed attempt.
Correction: Maintain continuous pressure and forward progression once you begin the pass. Do not pause between steps or allow breathing room. Each phase should flow into the next with constant weight and control, denying grip recovery opportunities.

Training Progressions

How do you train Knee Slice from Butterfly Half (Attacker)?

Phase 1: Hook Neutralization Mechanics - Butterfly hook killing techniques Practice only the hook neutralization portion against a cooperative partner who holds butterfly half guard. Work hip drops, shin pins, and direct hand control of the hook. Partner provides progressively stronger hook elevation attempts while you develop sensitivity to when the hook is truly dead versus merely suppressed. 5-minute rounds focused exclusively on killing the hook without proceeding to the pass.

Phase 2: Upper Body Control Integration - Combining crossface and underhook with hook control Add upper body control establishment to the hook neutralization drill. Practice the sequence of crossface to hook kill, or underhook to hook kill, developing muscle memory for the correct order of operations. Partner now resists upper body control and defends the hook simultaneously, forcing you to manage both challenges. Reset after upper body control is established—do not proceed to the slice yet.

Phase 3: Full Pass Execution at Low Resistance - Complete knee slice sequence with controlled partner Execute the complete pass from hook neutralization through side control consolidation against a partner providing 30-50% resistance. Focus on smooth transitions between phases rather than speed. Partner allows the pass to succeed but provides enough resistance to require correct technique at each stage. Drill 20-30 repetitions per round, refining the feeling of continuous pressure throughout the sequence.

Phase 4: Counter Recognition and Adaptation - Responding to defensive reactions during the pass Partner now actively defends using specific counters: butterfly hook elevation, knee shield insertion, underhook to dogfight, and deep half entry. Practice recognizing each counter early and applying the correct response. Build chains where a defended knee slice flows to smash pass, backstep, or re-establishment of position. Develop the if-then decision framework for each defensive reaction.

Phase 5: Live Positional Sparring - Full resistance application from butterfly half guard top Start in butterfly half guard top against a fully resisting partner. Top player’s objective is to pass to side control using the knee slice or any chain passing option that develops from it. Bottom player uses their full arsenal of sweeps and transitions. Track success rates over multiple rounds to identify which phases of the pass are breaking down and which counters you struggle to address.

Phase 6: Competition Integration - Applying the pass under match pressure conditions Incorporate the knee slice from butterfly half guard into full rolling sessions, specifically seeking the position during sparring. Practice setting up the passing attempt proactively by steering guard players into butterfly half guard configurations where you can apply the technique. Develop entries into the position from standing passing sequences and chain the pass with your existing guard passing system under time pressure and scoring conditions.

Safety Considerations

What are the safety concerns for Knee Slice from Butterfly Half?

When drilling the knee slice from butterfly half guard, exercise caution with the lateral pressure your slicing knee applies to the bottom player’s inner thigh and knee joint. Excessive force or incorrect angle during the slice can stress the MCL and meniscus of the bottom player’s trapped leg. Control your speed during the slicing phase, especially when the bottom player’s leg is entangled and cannot move freely. The crossface should apply firm but controlled pressure—avoid driving forcefully into the jaw or neck in a way that could cause cervical spine discomfort. Both partners should communicate about pressure levels throughout the drill. During live sparring, be particularly aware of knee position when the bottom player is actively defending, as unexpected directional changes can create dangerous twisting forces on trapped joints. If the bottom player taps or verbally indicates discomfort at any point during the pass, release pressure immediately.

Knee Slice from Butterfly Half Attacker

Outcomes