For more than 50 years having a flat reminder on the grip of your putter has been the accepted standard equipment for putting. With the invention of Science and Motion PuttLab, the ability to measure putting strokes precisely shows some very strong evidence that using a reminder grip or grip with a flat side may be a detriment. The following is an attempt to make my case.
1. We have to realize that in all golf swings, not just putting strokes, the club head moves in a circular motion. To try and do other wise is mechanically very difficult. Shoulders move in a circular motion around the spine, arms and hands move with the shoulders, also around the spine. So unless you can make your arms grow longer during the movement, the putter will move around the spine in a circle defined by the length of your arms. The arc at the bottom of the stroke will be straighter or more curved at varying degrees depending on the tilt of your spine and how far you are from the ball. The closer you are to the ball the more upright the circle and so the arc at the bottom of the circle with appear to move straighter than an arc tilted away from the ball.
2. The vast majority of golfers are more comfortable with the ball away from them when putting rather than close. Due to this set up most players swing the putter on a tilted circle that would create a curved path at the bottom.
3. We have found many of the golfers who mechanically are set up for a curved path try to swing the putter on the straighter line. This is the dilemma for most golfers. Trying to make the circular motion of the putting stoke match the imaginary target line that is straight. We call this steering the putter.
4. The desire to steer the putter is influenced by the references we use. A line on the putter, lines on the ball, and a flat reference on the top of the grip are all guides or aids to help us move the putter on a straight path.
5. It is easier to fix the steer than try to move the path to straight! There are physical reasons we stand off the ball. Vision, comfort and balance are not variables we can easily change to match a desired path. We can make the changes but over time we will regress to original position.
6. To help eliminate the steer it helps to eliminate straight line references. Especially the grip. As the putter swings and moves in the curved motion we still reference the flat portion of the grip to target. This conflict between perception – the straight line and actual path causes us to twist the putter as it moves along the path. The ball goes primarily where the face is pointed at impact as 82 % of the direction the ball leaves the putter is determined by face at impact. The twisting motion of the putter as we try to match curved to straight makes controlling the face of the putter much more difficult than if we simply allowed the putter to swing square to whatever direction the putter is moving during the stroke.
So by replacing the flat with a round reference on the grip we lose some of the urge to twist the putter while in motion. The “feel” reference of the straight line is gone and we are more likely to allow the putter to move freely with the path. Without the steer the results of the stroke become more predictable and our new found consistency makes us a better putter.