In her book “Fly Casting Techniques,” Joan Wulff writes:
“A good grip can enhance a cast; a poor grip can kill it. Your hand is the connecting link in the power sequence that starts in your muscles, is magnified by the rod’s action and is transferred, in the form of energy, to the fly line. The link must be secure.”
Take a second, the next time you are practicing and check your hand position before you make that cast. Is the rod where you want it to be in your hand? Did you start with your thumb “behind the cork,” and has it now shifted just a bit to one side or the other?
Most instructors generally teach people to use a thumb-on-top grip, but whichever grip you use – thumb on top, forefinger on top, or a thumb and forefinger extended grip, the key here is to be consistent on each cast.
One thing that I’ve noticed is that some anglers impact their cast because their grip will shift or move around from cast to cast, or sometimes even while false casting.
Can it hurt your cast? Yes. But with a little attention to detail, this is a casting problem that you can easily prevent.