Wednesday, November 19, 2008

Arc or Straight


The Putter Path Myth

The putter-face at impact determines approximately 82% of the direction of the ball moving away from the club. The remaining 18% of the direction the ball leaves the putter is influenced by the direction of the shaft plane as the putter swings through the ball. So the path the putter takes is of much lesser importance than the face angle at impact. However for the player, the perception of the direction of the putt is almost entirely the direction of the path of the stroke. The conflict can come either visually or by feel, but the results are usually the same as diagramed by the illustration at the top of the page. When a stroke starts "off line" it is the effort to correct, by twisting the putter-face or re-routing the putter during the forward swing that causes the miss. Trying to steer the putter in the forward stroke is easily the most frequent reason for a missed putt. If my stroke doesn’t match my perception of the direction I am trying to roll the ball as dictated by our vision, it is our nature to attempt to correct the error. This explains the success of having player not watch the putter as it swings away. They are less likely to react to the path created by alignment and posture and therefore less likely to attempt to correct the stroke. It also explains how for many of our students they are more successful by performing the stroke with their eyes closed. Without the visual influence or interference the stroke performs as it should.

There is also a great deal of misinformation out there due to the efforts to “market” aids and systems that are based on perfect path direction. Most teaching systems are based on achieving a putter path that parallels the intended line of the putt at impact. In general, there are two accepted descriptions of putter-paths, both of which assume a path that at impact has the putter moving in the exact direction of the intended line of the putt. These descriptions are known as the straight back and straight through method, which assumes that the head of the putter moves on a straight path during the stroke. The other method is called the arc. This is a description of the appearance of the putter when it is allowed to move on a natural inclined plane. Both of these descriptions are two dimensional descriptions of a three dimensional motion and the net effect is more confusion than solution. When measured accurately the putter actually does both. The shaft of the putter and the motion of the hands is a straight motion. We define this aspect as the stroke plane direction. The head of the putter, when examined separately moves on an elliptical path when traced in relationship to the ground and in two dimensions. This is because of the fixed length of the player’s arms and the attachment of a putter at a fixed length. As the shaft moves on a straight path along the inclined plane, as the putter head travels along as it comes up off the ground it moves along the plane slightly to the inside of the path of the shaft. The size and shape of the arc is determined by the distance the player is from the ball, the lie angle and length of the putter. The farther away the flatter the shaft plane angle and the more pronounced the arc. Because this path shape is a consequence of the stroke plane direction and the measurement and fit of the putter itself we feel the description of path shape to be of no importance.

Sunday, November 2, 2008

Ball Roll


Ths is a video of an average ball strike during a putt. Note the slight backwards rotation of the ball leaving the putter and that the ball imediately rotates forward on contact with the ground.