The Leading Edge, the Main Force Factor

A leading edge is a wedge, or a portion of your opponent's body that is going to break my alinement. When you're on the bottom playing guard, and i'm in half guard, or i'm inside control, whatever my opponent cross faces me, i'm establishing that the cross faces the leading edge. The main force factor is probably coming from that arm. That's what it's important to knock it flat, not get flattened out.