SINGLE-UNDERHOOK PASS

The single-underhook pass is the half-guard top technique in which the passer threads one arm under the bottom player's thigh and grips the lapel or belt with the underhooking hand, lifting the trapped leg slightly while walking around to the side. The technique is the middle ground between the over-under pass (both arms under) and the knee cut pass (no arms under), and it works particularly well against half-guard bottom players who have established knee-shield framing but have not yet won the underhook battle.

The entry begins from a half guard top position. The passer threads the inside arm under the bottom player's same-side thigh, grips the bottom player's belt or far lapel with that hand, and uses the underhook as a lever to lift the trapped leg while walking the free leg forward. As the bottom player's trapped leg lifts, the passer walks around to the side and drops chest pressure to consolidate side control.

What distinguishes single-underhook from the over-under is its use against the knee shield. The knee shield works by wedging the bottom player's shin across the passer's chest; a single underhook bypasses the shield because the arm goes under the leg rather than around the chest. This makes single-under one of the canonical answers to a defended knee-shield half guard. Bernardo Faria, Tom DeBlass, and the broader pressure-passing community in the 2010s and 2020s have used single-under as a primary half-guard pass, particularly when the bottom player has committed to knee-shield-based defense. Defensively the technique is countered by winning the underhook battle (the bottom player's underhook neutralizes the passer's), by sprawling the trapped leg backward to defeat the lift, or by snake-rolling out to recover guard.