I've found that it is roughly 1/3". 3" of DL =1" of tip movement. It varies some depending on the brace height and I assume other things affect it. If you figure 28" DL and 7" brace height that leaves 21" of power stroke. 7 and 21, that's a third, coincidence, probably. I always thought it would be 2 to 1 because it seemed like stretching a diamond to me. But you start out minus the brace height. I've only measured it on longer bows that you like so it may change with a short bow. Del mentioned a couple of times that he's measured it and got the same results I did. 3-1.