I've coached the So. CA. junior AAF teams, but the HS I work at is going in a new direction...trying to take the head out of the game so we brought in "Tip of the Spear" (Former NFL players) that developed a system of hands, hips, leverage of opponents pads to change the spine angle. There are some videos I'll look to find, and post. We had to basically go through two days of training before working with our boys.
our Var. line coach basically said, "We're holding on every play"... Same as the GB approach, but this "Tip of the Spear" operates on speed of hand strike at the cut of the pads...driving those pads up. Interesting approach...way different than the typical jab step, draw & strike. It's a "strike first" mentality, and even after two days of training I'm still wrapping my head around it