Lower Leg Shift Sweep
Half lower leg sweep — from Z-guard or half guard, near-knee hook and underhook sweep. Ducking to defend opens the back.
Adapted from InGrappling, Lower Leg Shift Sweep. System Games did not invent this curriculum.
Manage injuries →Position map Connects to 6 positions across 2 relationshipsOpen in the map →123456789←Enters from
The lower leg shift sweep is a half guard sweep that works by repositioning the bottom player’s trapping leg — the leg that is wrapping the top player in the half guard — from its standard half guard position to a hook behind the top player’s near knee. Once the lower leg is hooked behind the knee, the bottom player combines that knee hook with the underhook connection to drive the top player’s base backward and topple them to the underhook side.
The “shift” in the name refers to this repositioning of the lower leg. In standard half guard, the bottom player’s lower leg traps the top player’s leg between the bottom player’s knees. The shift moves that lower leg so the foot hooks behind the near knee rather than trapping the leg between the knees. This changes the mechanical function of the leg from a trap to a lever — instead of holding the leg in place, it now drives against the knee to disrupt the base.
This sweep is closely connected to the Z-guard position (also called knee shield half guard). From Z-guard, the bottom player already has a knee shield creating distance; the lower leg shift converts that structure into an active sweep rather than a passive frame. The underhook side determines the sweep direction throughout.
This is also the transitional movement that creates the scorpion position — the lower leg shift IS the scorpion entry. See the scorpion connection section below.
INV-11Invariant "The side of the body with the underhook controls the hip on that side. Hip control determines directional movement."
Why it works hereThe sweep direction is dictated entirely by which side the bottom player wins the underhook — pulling the upper body toward the underhook side matches the direction the lower-leg hook drives the near knee backward. If the top player has the underhook, the directional pull is inverted and the bottom player has no upper-body engine to combine with the knee disruption. Resolving the underhook battle is the structural precondition; the leg shift is the finishing mechanism.
See full invariant page → The underhook is the directional controller for this sweep. Before the lower leg shift is executed, the underhook battle must be resolved — the bottom player needs the underhook on the sweep side. If the top player has the underhook, they control the direction and the sweep cannot find its directional angle. Winning the underhook is a precondition, not an afterthought. The lower leg hook and the underhook work together: the underhook pulls the upper body in the sweep direction, and the knee hook disrupts the lower body base in the same direction.