Against opponents with significant skill and experience, I often find trouble in clearing the knee of a "good" half guard in order to pass, or work. Specifically, they are playing a smart, shallow half, with excellent control with the top knee to hinder the pass. In order to attack and pass, I have to clear that knee. Any tips? Without clearing the knee, I have success in taking an overhook, and cutting perpendicular to their body, before coming to north/south. There is risk of them shucking me and working to the back. To lesson back risk, I've used an underhook in similar fashion, but have been the victim of omoplata attacks and sweeps to an extent that I am not a big fan. I have tried to limit the sweep risk of clearing the knee by switching my hips and attempting to come to a reverse scarfhold, but when the opponent keeps a good half I am unable to free my trapped leg after switching hips.