2 Part Technique - Since the underhook is such a valuable asset in passing your opponent's half guard, it is crucial to dedicate some awareness to any of his attempts for escape or recovering full guard. Utilize Over Under Control to stabilize the top position, emphasizing the overhook with your weight while your underhook closes off space. If he begins to push your chest with his overhooked arm, switch to the control normally reserved for passing the no-gi half guard, i.e. Underhook & Head Control, so that you pin his arm between your chests and neutralize his ability to create room for escape. If while holding this no-gi control, he blocks your knee from reaching high enough for your foot to stomp his half guard, switch back to Over Under by scooping up his arm with your overhook. If his half guard is too high up on your leg for you to reach it with your free leg, use your overhook hand to push his knee within reach of your foot to step on. Do not telegraph your intention to free you knee from his half by proceeding slowly, otherwise he will counter by tightening. Unexpectedly burst your knee through, and then cut to the outside where you can establish side control for the pass.