How far forward should the number five strike go? I feel I know the answer but I am having trouble putting it into words for a younger student who keeps extending his arm all the way out (almost like he's doing a fencing thrust, but at lower midsection level). I'd like to give him a simple rule rather than having to keep saying "that's too far--you'd have no power there" but not giving more specific advice. I'm doing it as a straight-out thrust, not the upward hooking variation, though I myself always know I'm at the end of the thrust when my left hand slaps my right bicep.