Your demonstration of how you would defend yourself against 2 attackers is very good, I guess gary and Jim Doty are brothers, but I'm guessing if I was actually attacked by 2 people it's not going to be that easy.
A key element to the open-hand technique is to cock your thumbs. The first purpose is to intensify your palm strength. The second reason is to prevent thumb injury. Thumb injury is the most common in sports and other physical activities,
