"And guard yourself from all parries which the simple fencers execute, and note when he cuts, so you also cut; and when he thrusts, so thrust as well; and how you shall cut and thrust, you find that written in the five cuts and in the setting-aside." This is just some thoughts around parrying with Longsword, specifically parries execute by "simple fencers" or "holding against" parrying as Meyer calls it: Ox and Plough guard an Opening because "they are in essence the position of a thrust", i.e. they threaten a thrust. The key point however is that this is a counter attack (same tempo) action not a parry and riposte (two tempo) action. If you actually receive a Principle Cut to a high opening that you are covering in Ox you'll notice how you often get your hands cut, end up suppressed under his blade and are unable to riposte without some further work. Likewise if you receive a low cut in Plough your hands are vulnerable and he takes your ...