Also known as: knee slice · knee slide · knee cut
Cutting the knee through while they have the underhook.
Why it failsYou land on the wrong side of half guard with their underhook already in, and get swept by it.
FixWin or neutralise the underhook (cross-face, whizzer, shoulder pressure) before you cut.
Lifting the knee over their leg instead of slicing along it.
Why it failsThe lift creates space under your hips — exactly the space they need to recover guard.
FixSlide the shin down their thigh with your hip dropping toward the mat, keeping the space closed.
Letting your head drift to the same side as theirs.
Why it failsThey sit up into you, get the underhook, and reverse the position.
FixDrive the cross-face and keep your head past theirs on the far side throughout.