What must be established before attempting the knee slice from deep half guard?

Crossface control must be established first to neutralize the opponent's sweep mechanics. The crossface shoulder pressure turns the opponent's head away, collapses their upper body structure, and reduces the effectiveness of their deep underhook. Without crossface, any knee lift creates an immediate sweep opportunity for the bottom player.

Your opponent maintains an extremely tight underhook on your far leg that you cannot break - what alternative approach should you consider?

If the deep underhook is unbreakable through standard grip fighting and pressure, switch to a backstep pass rather than forcing the knee slice. The backstep works with the opponent's underhook grip rather than against it, stepping your trapped leg back and around to pass in the opposite direction. Continuing to force the knee slice against an unbreakable underhook wastes energy and creates sweep opportunities.

What is the most critical moment of vulnerability during the knee slice from deep half?

The most critical vulnerability window occurs when your knee lifts off the mat to begin the slicing motion. At this moment, you temporarily lose base and hip pressure, creating the exact conditions the bottom player needs to execute sweeps like the Homer Simpson or waiter sweep. This is why committed forward drive must accompany the knee lift, and why the free leg must be posted extremely wide for stability.

You feel your opponent beginning to elevate their hips as you start the knee slice - how do you adjust?

Immediately increase forward and downward pressure through your crossface and chest to kill their elevation. Drop your hips lower and widen your posted leg base. If the elevation is significant, abort the knee slice attempt temporarily, focus on flattening them completely, and only reattempt once their hips are back on the mat and their elevation threat is neutralized.

Why should the knee stay low during the slice rather than lifting high over the opponent's body?

Keeping the knee low maintains maximum contact with the opponent's body, preventing space creation that they can exploit for guard recovery or hook insertion. A high knee path creates a gap between your body and theirs, allowing them to insert feet, hooks, or frames that stall or reverse the pass. The low diagonal path also keeps your center of gravity lower, maintaining better balance throughout the transition.

What is the correct direction of force during the knee slice pass?

The force should be directed forward and diagonally downward through your crossface shoulder and chest into the opponent's upper body, while the knee cuts along a low diagonal across their hip line. The combined force vector flattens the opponent while the knee separates their legs from their body. Avoid upward or purely lateral forces, as these create space rather than pressure.

Knee Slice from Deep Half Attacker | BJJ Technique Guide

As the top player in deep half guard, the knee slice pass is your most direct route to side control when you have established sufficient upper body control to begin leg extraction. The technique demands that you first neutralize the bottom player’s sweep leverage through crossface pressure and weight distribution, then commit to driving your knee across their body with decisive forward momentum. The critical challenge is managing the brief instability created when your knee lifts to slice, as this is precisely when your opponent will attempt their highest-percentage sweeps. Success requires blending pressure, timing, and commitment into a single coordinated action that overwhelms the guard player’s defensive structure.

From Position: Deep Half Guard (Top)

Key Attacking Principles

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

Establish crossface control before attempting any leg extraction to neutralize sweep mechanics
Drive forward pressure through your shoulder and chest to flatten the opponent and collapse their underhook leverage
Commit fully to the knee slice once initiated - hesitation creates sweep opportunities
Maintain hip-to-hip connection with your free leg posted wide for base throughout the transition
Use your lead knee as a wedge that separates the opponent’s legs and body simultaneously
Time the knee slice for when the opponent’s underhook grip is weakest or when they are recovering from a failed sweep attempt
Keep your trailing leg ready to sprawl or post if the opponent attempts to elevate during the pass

Prerequisites

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

Crossface or strong head control established to limit opponent’s ability to generate sweep rotation
Trapped leg has sufficient range of motion to change angle and initiate the knee cut across opponent’s body
Free leg posted wide with solid base to maintain balance during the transitional moment of the slice
Opponent’s deep underhook grip weakened through shoulder pressure, wrist control, or positional adjustment
Weight distribution forward and low enough to prevent opponent from creating elevation for sweep

Execution Steps

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

Establish Crossface and Settle Weight: From deep half guard top, drive your crossface shoulder into the opponent’s jaw and neck, turning their head away from you. Settle your chest weight onto their upper body while keeping your hips mobile. Your free hand should control their far hip or underhook their far arm to prevent frame creation.
Weaken the Deep Underhook: Apply constant downward shoulder pressure to compress the opponent’s underhook arm. Use your near hand to strip or peel their grip on your far leg. You can also use a whizzer or overhook to further compromise their underhook control. The goal is reducing their grip strength enough that your leg can move.
Post Free Leg Wide for Base: Position your free leg in a wide post to the outside, creating a stable tripod base. This leg is your primary balance point during the pass and must be far enough out to prevent the opponent from using your momentum against you during the knee slice. Think of it as an outrigger stabilizer.
Begin Knee Angle Change: Start rotating your trapped knee outward and upward to create the slicing angle across the opponent’s body. Keep your upper body pressure constant as you begin this movement. The knee should angle toward the opponent’s far hip, creating a diagonal line across their torso. Do not lift your knee high off the mat initially.
Drive Knee Across with Forward Pressure: Commit to the knee slice by driving your knee across the opponent’s thigh and hip line while simultaneously increasing crossface pressure. Your shin should create a diagonal barrier across their body. Drive forward with your hips as the knee cuts through, using your body weight to power the pass rather than just leg strength.
Clear the Legs and Consolidate: As your knee clears past the opponent’s hip line, immediately slide your shin to the mat on the far side. Maintain crossface pressure throughout to prevent the opponent from turning into you or recovering guard. Your trailing leg should follow through to establish proper side control positioning with hips low and heavy.
Settle into Side Control: Complete the pass by establishing perpendicular chest-to-chest contact with your hips heavy on the opponent’s hips. Secure your crossface or underhook, and position your near knee tight against their hip to prevent guard recovery. Transition your grip from the passing configuration to standard side control controls within the first two seconds of arrival.

Possible Outcomes

Result	Position	Probability
Success	Side Control	50%
Failure	Deep Half Guard	30%
Counter	Half Guard	20%

Opponent Counters

How might your opponent counter Knee Slice from Deep Half?

Opponent maintains tight deep underhook and blocks knee extraction (Effectiveness: High) - Your Response: Increase crossface pressure to flatten their upper body, use near hand to strip grip on your leg, and consider switching to a backstep pass if the underhook remains unbreakable → Leads to Deep Half Guard
Opponent times a Homer Simpson sweep as your knee lifts off the mat (Effectiveness: High) - Your Response: Post your free hand on the mat immediately and sprawl your trailing leg back to base out. If the sweep is advanced, abandon the knee slice and focus on base recovery before reattempting → Leads to Half Guard
Opponent elevates hips into waiter sweep during the transitional moment (Effectiveness: Medium) - Your Response: Drive your weight forward and down into their chest to kill the elevation. Widen your base with the posted leg and focus on smashing their upper body flat before reattempting the slice → Leads to Half Guard
Opponent frames on your hip with free hand to create distance and block the knee path (Effectiveness: Medium) - Your Response: Swim through the frame with your near arm or pin their framing wrist to the mat. Increase forward pressure to close the distance their frame created before continuing the knee slice → Leads to Deep Half Guard
Opponent transitions to X-Guard or Single Leg X by hooking your posted leg (Effectiveness: Medium) - Your Response: Immediately backstep your posted leg out of their hook range. Drop your hips and drive crossface pressure to prevent them from establishing the new guard position → Leads to Deep Half Guard

Common Attacking Mistakes

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

1. Attempting the knee slice without first establishing crossface control

Consequence: Opponent’s head and upper body remain free to generate rotation for sweeps, making the pass attempt an invitation for Homer Simpson or waiter sweep
Correction: Always establish crossface as the first step. Drive shoulder pressure into opponent’s jaw to turn their head before attempting any leg movement. The crossface is the foundation of the entire pass.

2. Lifting the knee too high during the slice creating excessive space

Consequence: Creates a large gap between your body and the opponent, allowing them to insert hooks, recover guard, or initiate sweep mechanics using the space
Correction: Keep the knee close to the opponent’s body throughout the slice. The knee should cut along a low diagonal path across their torso rather than lifting up and over. The shin should maintain near-contact with their body.

3. Insufficient base with the free leg during the transitional moment

Consequence: Without a wide posted leg for stability, any elevation or rotation from the opponent easily disrupts your balance, resulting in sweeps
Correction: Post your free leg wide to the outside before beginning the knee slice. This leg is your primary balance mechanism. It should feel uncomfortably wide - if it feels natural, it is probably not wide enough.

4. Hesitating mid-slice and stopping with the knee partially across

Consequence: A stalled knee slice leaves you in the worst possible position - partially committed with reduced base and no positional advantage. The opponent can easily counter a stalled pass attempt
Correction: Once you commit to the knee slice, drive through to completion with conviction. If you feel the pass stalling, either commit fully with increased forward drive or abort completely and reset rather than parking halfway.

5. Relying on leg strength rather than body weight to power the pass

Consequence: Muscling the pass is exhausting and creates tension that the opponent can redirect into sweeps. It also lifts your weight off the opponent, giving them space to work
Correction: Drive the pass with forward body pressure and hip weight. Your chest and shoulder do the flattening work while the knee follows the path created by your upper body pressure. Let gravity and body weight do the heavy lifting.

6. Releasing crossface pressure during the completion phase of the pass

Consequence: Even after clearing the legs, releasing crossface allows the opponent to turn into you, insert a knee, and recover half guard before you consolidate side control
Correction: Maintain constant crossface pressure from initiation through completion and into side control consolidation. The crossface should intensify as you complete the pass, not decrease.

Training Progressions

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

Phase 1: Mechanics - Basic movement pattern and body coordination Practice the knee slice motion with a cooperative partner. Start in deep half guard top with crossface established. Focus on the coordination between crossface pressure, knee angle change, and forward drive. No resistance. Perform 20 repetitions per side emphasizing smooth connected movement.

Phase 2: Timing and Pressure - Weight distribution and timing the slice Partner provides light resistance from deep half bottom, attempting basic grips and minor elevation. Focus on feeling the correct timing to initiate the knee slice, maintaining pressure throughout, and recognizing when the pass is available versus when to reset.

Phase 3: Counter Integration - Responding to defensive reactions during the pass Partner defends with specific counters: frames, underhook retention, and sweep attempts. Practice adjusting your pass in real-time based on their reactions. Build automatic responses to the three most common defensive reactions.

Phase 4: Live Application - Full resistance positional sparring Positional rounds starting in deep half guard top. Attempt the knee slice against full resistance while partner works their full deep half game. Track success rate and identify patterns in when the pass succeeds versus fails.

Phase 5: Chain Passing - Integrating knee slice into passing sequences Practice using the knee slice as part of a broader passing system. When the knee slice is defended, transition to backstep or smash pass. When those are defended, return to knee slice. Develop a flowing passing game that uses each failed attempt to set up the next.

Safety Considerations

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

The knee slice from deep half guard involves significant pressure on the opponent’s neck and face from the crossface, as well as knee pressure across their body. Apply crossface with controlled force, avoiding excessive cranking of the neck. During training, communicate with partners about pressure intensity. Be cautious of your knee landing on the opponent’s ribs or hip bones during the slice. If the opponent taps due to pressure rather than submission, release immediately and adjust your technique to distribute pressure more broadly.

Knee Slice from Deep Half Attacker

Outcomes