Center of Gravity (CG)
How often we find in the descriptions of clubs, the term "center of gravity" more often abbreviated with the acronym CG? But what is it and how it affects our game?
The center of gravity of a system is the geometric point corresponding to the average value of the mass distribution of the system in space; to put it more simply, it’s the point of intersection of all the balance points of an object.
But the CG is a single point within the clubhead therefore it must be defined in 3 dimensions. This means that the head of a golf club has a CG of the vertical position (as it is in the top of the head than the sole) of the horizontal position (how far it is from the central axis of the shaft at the height of the hosel) and finally how much it’s backward to the face.
The lower and backward is the CG and the higher will be the trajectory of our shots to loft equality; between the two positions the one which affects more the height of the shot is how much is set back from the face of the club with respect to how much is from the sole.
The horizontal position of the CG, or we can say also how far it’s from the center axis of the shaft, is a design factor of the club that affects the accuracy of the shot; if the CG is closer to the axis of the shaft there will be less tendency by the player to push or fade and vice versa. The reason for this is that the closer the CG to the shaft the lower is the Moment of Inertia (MOI) of the axis of the shaft and larger will be the player's tendency to rotate the face of the stick less open (or closed) on impact with the ball. Obviously the opposite if the CG move away from the axis of the shaft.
Initially, the position of the center of gravity is determined by the width, height and depth of the head; after which varies depending on how the weight is positioned inside the head. More high will be the head or higher is the weight and the higher will be also the CG and vice versa.
Deeper will be the head and the CG will be set back and thinner will be the head and the CG will be close to the face.
Finally, the longer the head from heel to toe, or more weight will be placed on the toe of the head, and the CG will be more distant from the axis of the shaft and the opposite if the length will be less or if the weight will be put towards the heel stick.