Why Your Ball Slices and Hooks
By T.J. Tomasi
Universal Press Syndicate
Knowing why your ball flies the way it does gives you the power of intervention, so if you don't like the ball flight, you can change it.
The spin on the golf ball comes from its rotation around its axis ― you can draw an imaginary line through the center of your golf ball at 90 degrees and that's your axis. When you hit the ball with a clubface that is not perfectly square to the path of your club, the axis of your ball tilts either to the left or right as the ball leaves the face. It is this tilt that causes your ball to curve.
If your clubface is open to the path, it's a slice. If it's closed, you'll hit a hook. A square clubface at impact causes no axis tilt so the ball rotates with backspin only, and the shot goes straight with no curve.
So if you're slicing or hooking, you can fix the curve by fixing your clubface. Below are some of the most common causes of an off-line clubface, but since the causes vary depending on the player, I suggest an appointment with a good teacher who can show you the specific adjustments you need to make.