The best part of the hand to stop the rod abruptly and to make a powerful back cast is the pisiform bone. It’s a small bone at the end of the hand’s heel.
Picture of my right hand showing the location of the pisiform bone (white arrow). The area is red because I was flexing the bottom section of my rod against the underside of a table — as if to make a powerful back cast.
To position the pisiform bone on top of the handle, the forearm must be rotated inward (or pronated) so that the palm of the hand faces downward when holding the rod horizontal to the ground.
What Are Options For An Efficient Grip?
With this hand position, there are several choices for a grip. Let’s go over some classic ones.
Various grips that place the pisiform on top of the handle: the key grip (left), the V-grip (middle) and the finger-on-top grip (right).
The Key Grip
In this grip, the rod handle is held as if it was a thick key. The bones at the base of the index finger (on the opposite side of the knuckle) are used to push or rotate the rod forward. The pisiform bone is used to stop the rod abruptly and to push or rotate the rod backwards. The bones in the thumb and the index finger help stabilize lateral movements. The handle is held primarily in the bony parts of the fourth and fifth fingers.
The key grip is a choice of many world-class casters who compete for distance and accuracy.
The V-Grip
In many circles, the key grip is also known as a V-grip. However, there are some subtle differences in my mind. In the V-grip, the thumb tends to assume a position that is halfway between thumb-on-top and the key grip. The bones at the base of the index finger tend to sit on the upper, slightly outer side of the handle. Consequently, both the thumb and the bones at the base of the index finger are used to push or rotate the rod forward. The pisiform bone still contacts the topside of handle.
Side profile of the V-grip. While it may not look like it, the pisiform is firmly placed against the handle.
The Finger-On-Top Grip
A finger-on-top grip is also another option that, when used properly, places the pisiform bone on top of the handle. The biggest problem with the finger-on-top grip is that it doesn’t allow the caster to create as much power during the front and back casts as the key or V-grip. The main reason is that the finger-on-top grip restricts the wrist’s range of motion.
This restriction of wrist motion is also a problem with the thumb-on-top grip. The role of the wrist in the cast will be discussed in another article, but a range of motion is important.
One More Consideration for A Grip
There is one drawback that we should discuss that affects all grips, but to different degrees. If you start in the bottom position of a cast with a thumb-on-top grip and you bring your hand up to the top position as if you had made a back cast, you should notice that your thumb naturally points slightly behind your head. If you were holding a rod, the rod tip would have swung off a straight (forward-backward) path.
The key grip, V-grip and finger-on-top grip are arguably less prone to this problem since the thumb is already pointing inwards (due to the forearm rotated inward or pronated) during the entire cast.
The Bottom Line
The discussion of grips could continue, but the remaining considerations are less important. While it’s true that you can start casting with any grip, the choice of grip affects how long you can fish, your ability to improve, and how quickly you progress.
The key and V-grips are bony grips because you are literally holding the rod with the bones of your hand. A bony grip has several advantages. We’ve discussed the first one: energy transfer is more efficient.
Another advantage is that you will be able to relax your grip during the entire cast and for your entire day of fishing: no more shaking out the hand, no more numbness in the fingers, and no more pain due to grip fatigue.
So, use the hardest parts of your hand to grip the rod as softly as possible. Fly casting is all about conservation of energy and efficiency.