I feel a good % of the time when a deer jumps a string is do to the hunter....shifting feet, arrow draw, and countless other things. I personally have never seen a deer jump the string when someone has been at full draw and takes a steady shot. Not saying they can't, but never seen it. Alot of hunter shift there wieght right as they shoot. I think that thismay be causing the string jumpers, my girl friend is the queen of moving before the shot. Don't tell her I said that