The diagram above is meant to depict two different ball launch conditions off a putter. The top shows a putter with 0 degrees shaft lean and 2 degrees of loft. The bottom diagram shows the same putter with 4 degrees of shaft lean and -2 degrees loft at impact. The difference to the player? At the top the grip might be pointed at your belt buckle, while the forward lean would be trending toward your lead pocket.
This is a simple example of two common schools of thought on how to launch a ball off the putter to get the ball rolling as soon as possible. But before we discuss the two methods lets clarify a couple of things.
1. Ball roll is a function of the forward momentum of the ball combined with the friction from the ground. so as the ball moves toward the target the ground resists, causing a forward rotation of the ball. Eventually as the forward momentum dissipates the ball rolls continuously along the ground. At this point we have reached what many of my colleagues refer to as true roll. So the theory is that the lower you launch the ball the sooner the ground reacts to the ball and true roll happens quicker. Depending on the launch angle this happens at anywhere from 10 -20 percent of the distance of the putt. This skid phase is essential in having a putt roll.
2. There is a fine line between skid and bounce. If you launch the ball at a greater angle, say more than 3 degrees, the ball literally lands and bounces up. This minimizes the time on the ground in the early phase of the putt and reduces the friction between the ball and the ground. This delays the influence of friction and when the ball begins to roll.
In the next post we will begin to discuss the differences between the two.