Sloppy head action leads to fat shots. Not only should you keep your head in the same place during the swing, but consciously avoid head motion that's downward or to your right.
Many top golfers' heads do move a little downward and to the right in response to the targetward thrust of the lower body. But if the motion becomes accentuated, they--and you--will surely catch the ground before the ball.
Fat and thin shots are caused by the same problem: The club bottoms out before the ball. The cause often is that the swing is out of sequence. When I get out of sync--say, an overactive lower body--I feel I'm late with my hands, so I release the club to catch up. And I hit it fat.
This usually happens when you try to do something you shouldn't do, like hit a very hard or very soft shot. That's why it's critical to learn one swing, and adjust your grip or stance, rather than changing your swing.
The late Jim Flick always said, "Measure yourself to where you want to be, and then stay level." That's why I start with the club slightly off the ground. The momentum of the swing pulls the club down to the ball. If you start with the club on the ground, you're setting up for a fat shot. I measure for a solid strike, then stay level.
JACK NICKLAUS writes articles exclusively for Golf Digest. This is the third in a series of pieces in which Nicklaus looks back at his earlier writings in Golf Digest.