Good form in any physical activity must be valued in terms of efficiency. The efficiency of a thermal engine, for example, is measured by the ratio of the work done by the engine to the heat energy supplied to it. The efficiency of a golf stroke must be measured, in the same way, by the ratio of the work done on the ball to the amount of physical energy used up in the swinging. The expert golfer drives far with little apparent effort because of the high rate of efficiency of his performance. The duffer, though he strain himself to the utmost, falls far behind because so much of the energy expended goes to waste.

Efficiency Depends on Three Things

A high rate of efficiency, and hence good form, in golf, depend upon three things; the development of the greatest possible club-head speed at contact, with whatever energy or power the player can supply—the production of a precisely accurate contact between club and ball, directing the blow along the line upon which it is intended the ball shall travel–and consistency in per-forming approximately according to these ideas.

Although these are obvious generalities, it is helpful to do a little thinking along these lines in order to appreciate the importance to a golfer of a proper use of his left arm. For it is in this particular that all duffers are most appallingly deficient, and here too that the better players most often go astray.

Straight Left Impossible for Some

For some persons a straight left arm is a physical impossibility. So let us say, that an extended left arm is one of the prime requisites of good form. In many ways it contributes to club-head speed, accurate contact, and consistency of performance, the three components of the efficiency rate.

Just now we are interested chiefly in the backswing. The backward movement is merely the means of storing up power to be used in the hitting, but to increase the amount of this stored up energy is of first importance. We have seen that the beginning was made in the hips in order to assure that the wind-up of the body would at least be started. When this had progressed a short distance we began to force the club back with the left arm.

Now with the club having completed about half of its backward travel, the left arm has become almost straight, and is pushing the club as far back as it can comfortably go. The arc of the swing is thus made very broad so that the space and time for adding speed to the club-head coming down will be as great as possible.

The player who allows his left arm to bend perceptibly, as illustrated in figure 5, is sacrificing breadth of arc and power. His swing, because it is not as wide as it could be, is that much away from the ideal efficiency, which he could make it.

Figure 5