The definition of a pendulum is a weight that is hung from a fixed point so that it can freely swing. Creating a pendulum in your putting stroke, does exactly this.
It creates a stroke that freely swings, has tempo to the movement and swings in a straight line, making it a highly desirable putting action as you will hit a lot of accurate putts with this method.
The pendulum in a putting stroke is created between your arms and the putter. The fixed upper point of the pendulum is your shoulders, which are used to control the swing of the putter. The weight of the pendulum is the putter head and between these two points there is one rod of your arms and the putter shaft. There is no hinge involved in a pendulum. The pendulum rod swings as one rod. In creating a putting pendulum, your arms and the putter work as one unit, or rod, with no hinging action at your wrists. This ensures that a constant swing is created that delivers a constant tempo making distance control much easier.
To create a pendulum putting stroke, initially set your feet up just under shoulder width apart and maintain an even balance between your feet. Position the ball in the centre of your feet. Position your eyes directly over the golf ball. If you are not sure if you have achieved this or not, take an additional golf ball in your hand and once you are set up in your posture, ready to play the putt, place the additional golf ball between your eyes on the bridge of your nose. Simply let this ball now drop to the ground and it will drop vertically. If it hits the ball you are ready to play, then your eyes are set up directly over the ball, which is what you are looking to achieve in a pendulum putting stroke. If the ball does not drop on to the ball to be putted, then adjust your distance from the ball accordingly and repeat the drill, until you do drop the ball on to the other one on the ground.
In creating an effective pendulum, which swings in a direct line back and forth, the upper part of the pendulum needs to be fixed above the weighted part. Setting your eyes directly over the golf ball will allow your shoulder position (the fixed part of the pendulum) to be set in a way that allows your arms to dangle directly under your shoulders and hang freely. If you now hold the putter in this position where your hands are dangling in, you will be able to swing the weight of the pendulum that you have created (the putter head) directly back and forth along the target line. With the putter face aiming along the target line and the putter head swinging along the target line, you will now hit straight, highly accurate putts, directly along the target line.
To ensure that you are controlling the swing from your shoulders rather than using your wrists and hinging incorrectly, work on keeping your wrists really passive. To get the feeling of this, hold the putter much lower down on the handle and position a golf ball in the gap that is created between your left wrist and the putter handle. Play your putts when you are practising like this and keep the ball in that position. This will ensure that you are maintaining your wrist angles and as a result you will be controlling the putter from your shoulders.
Using a pendulum putting stroke will really improve your putting as you will strike the ball much more accurately along the target line and you will find that you deliver a more constant tempo and club head speed to the golf ball, making distance control much easier, as you will control the distance of your putts with your swing length. As a result you will take fewer putts around the green and you will notice that as a result, your scores get lower.