It‘s good for your game
Feel the heel in your target hand
A good golf grip activates the muscles you want to use in the golf swing, while an incorrect grip encourages use of the wrong muscles.
Take your grip with your arms fully extended in front of your chest and close your left hand (right for lefties) around the club handle. You should find that your left thumb falls slightly to the right of the top of the handle.
This places your wrist square to the clubface, which is important because when centrifugal force straightens your arms through impact, your wrist joint, elbow joint and shoulder joint seek alignment. Therefore, the clubface must be set at address to prepare for the inevitable alignment of those joints. (Note: Ignore the markings on the grip; they are not meant as guides for your hands.)
Your target thumb (the thumb of the highest hand on your grip) plays a major role in the rotation of the clubface through impact. In addition to its anchoring capabilities, your top thumb's position on the club handle determines the direction in which force is applied to the shaft during your release, and therefore how much the face of your club will rotate through the impact.
When your thumb is on the top of the shaft at address, pressure is exerted down the middle of the club shaft, reducing clubface rotation through impact and, unless there is compensation, you'll hit a fade or a slice. With your target thumb down the back of the shaft, the direction of the force causes your clubface to rotate aggressively through impact, imparting the characteristic spin of the draw shot.
Another important aspect of thumb positioning influences the length of your golf swing, and that is the grip length of your lead thumb. You can retract your thumb so that only the tip of it touches the grip (called the short thumb), or you can use the long thumb, where all of your thumb touches the grip. The medium thumb is in between.
If you want to lengthen your swing and increase your distance, use the long thumb, especially if you are short on physical strength. For a short swing, use the short or fully retracted thumb as some very powerful players with big chests do. And if you're in the middle in physical strength and are looking for a combination of distance and accuracy, try the medium thumb as I am demonstrating in the photos.
Tomasi writes for Universal UClick.