The Underhook Is Doing 70% Of Your Game Whether You Know It Or Not — Mechanics + Drills

The bottom player in half guard gets passed. The top player in side control gets swept. The wrestler gets taken down from the standing exchange. Time and again, the advice is generic: "Work your guard retention," "Maintain pressure," "Keep your head up." This isn’t a self-help seminar; it's a technical discipline. If you’re experiencing these failures, it’s highly probable your underhook game is underdeveloped, misunderstood, or simply not present when it needs to be. This isn't an accessory; it's the primary engine of offense and defense across at least 70% of your BJJ repertoire. Neglect it, and your game will feel fragmented, reactive, and perpetually behind.

The underhook is not merely a grip; it is a full-body connection, a lever, and a framing device all in one. Its efficacy stems from its ability to disrupt an opponent’s base, create angles, and generate powerful positional changes. Many practitioners view the underhook as a defensive tool – a way to prevent the opponent from getting to your head or to establish a frame. This is a critical misunderstanding. The underhook, at its core, is an offensive weapon. It dictates where your opponent can go and, more importantly, where they cannot.

The Underhook: Mechanics of a Lever

Forget the simplistic notion of "just getting an arm under." A functional underhook is a system. It begins with depth. Your bicep should be connected to your opponent's lat, tricep to their rib cage, and your shoulder driving into their armpit. Your hand, often seen as the "grip," is largely irrelevant for the initial establishment and much of its power generation. Your forearm and shoulder are the primary tools.

Establishing the Connection

When you secure an underhook, your elbow must point down towards the mat, or at least towards their hips, not flared out. A flared elbow provides no leverage and is easily collapsed. Your shoulder is the wedge. You are not just sliding your arm underneath; you are driving your shoulder into their armpit, creating space for your arm, then collapsing that space with your arm to achieve a tight connection. Your head positioning is critical. Your head should be on the same side as your underhook, driving into their shoulder or chest, completing the frame and connecting your spine to the leverage point. This is the difference between a loose arm under an armpit and a structural, powerful underhook.

The underhook's power comes from its ability to disrupt your opponent's posture and base by attacking their line of gravity. By driving your shoulder and connecting your hips, you force their weight onto a compromised base, making them vulnerable to sweeps, reversals, and transitions. Your hips must follow your underhook. If your underhook is deep and active, but your hips are static, you are not truly leveraging your body weight. The underhook becomes the precursor to hip movement, enabling effective shrimping, sit-outs, and technical stand-ups.

The Underhook in Action: From Guard to Takedowns

The underhook's versatility is its defining characteristic. It bridges the gap between positional control, offensive attacks, and defensive scrambles across almost every position.

Side Control Escape and Guard Retention

When trapped in side control, the knee-on-belly, or even scarf hold, your first instinct might be to frame with your arms or bridge. While these have their place, the most potent escape involves acquiring an underhook. Your opponent’s top pressure often relies on keeping your hips flat. An underhook allows you to rotate your body, elevate their torso, and create the essential space to recover guard.

Your arm that is under your opponent's armpit is creating a wall with your tricep and shoulder. This wall prevents them from collapsing their weight directly over your chest and head. More importantly, it gives you a lever to turn your hips. Without this lever, shrimping becomes an exhausting, inefficient struggle against gravity and pressure. With it, you are leveraging your entire skeletal structure against theirs.

Half Guard: The Dominant Lever

In half guard, the underhook is arguably the single most important grip. For the top player, it allows for heavy pressure, passing, and submission setups. For the bottom player, it’s the gateway to sweeps, back takes, and deep half.

#### Top Half Guard: The Pressure Pass Engine

From top half guard, a deep underhook on your opponent's far arm is a game-changer. It neutralizes their ability to recover their knee shield or elevate you for a sweep. When Lucas Lepri passes, his underhook is often a primary component of his pressure game [2]. He uses it to flatten his opponent, pin their shoulder, and limit their hip movement, allowing him to cycle his legs for a knee slice or a body lock pass. The key here is not just getting the arm under, but using your chest and head pressure to drive into their underhooking arm, effectively "pinning" their shoulder to the mat. Your underhook becomes a tool to further smash them, controlling their upper body while your legs disentangle.

#### Bottom Half Guard: The Offensive Gateway

From the bottom, the underhook transforms half guard from a defensive stall to an offensive launching pad. When you have a deep underhook, you connect your entire body to your opponent's far hip. This allows you to off-balance them, lift them, and initiate sweeps or transitions to the back.

Back Control and Transitions

The underhook is crucial for both taking and defending the back. When attacking from turtle, a deep underhook allows you to sit your opponent to their hip, making them vulnerable to the seatbelt grip and back exposure. Conversely, if you are turtled and your opponent has a seatbelt, creating a strong underhook with your defensive arm can prevent them from fully securing the position, allowing you to turn in or stand up.

Consider Marcelo Garcia's genius [3]. While known for his guillotine, much of his attacking game, especially his single-leg entries from the feet and his transitions to the back from front headlock positions, relies on establishing dominant underhooks. He uses the underhook to off-balance, drive into, and then rotate his opponents onto their side or back. It's a fundamental principle: control the far shoulder, control the body.

Standing Wrestling and Takedowns

Any grappler with a wrestling background understands the underhook's primacy in standing exchanges. It is the core grip for controlling posture, breaking balance, and setting up takedowns. From a simple collar tie, a deep underhook allows you to pummel your opponent to their hip, clearing the path for single legs, double legs, or even upper body throws. The principle is identical to the ground game: connect your bicep to their lat, drive your shoulder, keep your head connected, and turn your hips.

Common Underhook Misconceptions and Errors

1. The Shallow Underhook

Many practitioners only get their forearm under, with their bicep barely touching their opponent. This is not an underhook; it's a weak frame. It offers no leverage and is easily nullified. The underhook must be deep, connecting your bicep to their lat and your shoulder to their armpit.

2. The Static Underhook

Treating the underhook as a static frame prevents you from realizing its offensive potential. It's a dynamic lever. You must constantly adjust its depth, angle, and connection to your hips to create movement and off-balance your opponent. If you just hold it, it will eventually be flattened or neutralized.

3. Neglecting Head and Hip Connection

The underhook gains its power from the entire body. If your head is not on the same side, driving into your opponent, or if your hips are not moving in conjunction with your underhook, you are losing significant power and leverage. The underhook is a conduit for full-body force, not an isolated arm grip.

Drills for Underhook Dominance

Mastering the underhook requires consistent, deliberate drilling focused on the core mechanics of connection, leverage, and movement.

The underhook is not an advanced technique for black belts; it is a foundational principle that must be understood and drilled from white belt onward. If your game feels stagnant, if your guard constantly gets passed, or if you struggle to maintain top control, the answer isn't always more drilling of esoteric techniques. Often, it's a return to first principles: a deeper understanding and application of the underhook. It is the universal solvent for many of BJJ's most frustrating positional problems. Stop just framing; start leveraging. Your game will thank you for it.