That' s a general rule of thumb and not necessarily set in stone. The shorter the brace height the longer the arrow is attached to the string and the more prone it is to flaws in your release and form. Now with saying that My Parker has a brace height of just over 7 inches and I have a 31 inch draw length. So, you could have a brace height of 3 inches and all else being equal the arrows would leave the string at the same time.



IMO the shorter draw length you have the less brace height you can have and still have a pretty forgiving bow.