When the eye has become accustomed in billiard playing to the required angles of divergence of the balls after ball or cushion contact, and when the mind has grasped the degrees of contact and power—sometimes accompanied by enhanced horizontal, vertical, or diagonal rotation of the cue ball by the application of side that are necessary to produce the required divergence, little remains to be done by the cueist beyond that nice adjustment of "strength" which is essential if all other knowledge and ability are not to be neutralized and spoiled.
"Strength" really resolves itself into "swing" and in all strokes except stun, stab, and masse, into free swing; and probably the best first lesson that a billiard student could take would be to seat himself for ten minutes in front of a clock and note the rhythmic and flowing action of its pendulum— regular, unfettered, and unhurried. Imagining the right-hand swing of the pendulum to represent the withdrawal of the cue from the ball and the left-hand swing to represent the cue swing at the moment of contact, the student has only to remember that the final forward swing should be slightly accentuated and the cue held quite horizontally, and he will have absorbed an extremely valuable elementary lesson which thousands of players go through the whole of their billiard life without acquiring or even dreaming of.
There is no game played with a stationary ball in which this easy and sensitive swing is not vital. It is the same in golf, croquet, and hockey, as it is in billiards. The golfer who swings in his drive instead of striking sends the ball much farther with half the exertion of the mere "thrasher," and exactly the same thing applies to croquet and to hockey. We are not sure that it does not also apply to cricket, tennis, and rackets, and that that comfortable feeling experienced when the ball is returned smoothly and sweetly off the bat, instead of making its impact felt in an unpleasant vibration, is not referable to the same source.
In billiards another excellent effect is produced by the cue swing, which is delightful to note and experience. Not only does the cue ball under these conditions go on its mission freely and sweetly, but the object ball against which it is directed does the same. This is illustrated in a remarkable manner by the long loser, especially when there is, in addition to the proper swing of the cue, just a modicum of top on the cue ball. Two players shall be put to this stroke, the one flogging the ball and the other restraining his force but preserving an easy and even cue swing, and the result will be that, whilst, in the one case, the object ball lags in a dull, heavy way, in the other it springs from cushion to cushion as though invested with life and sensibility.
The theory of the swing, as gathered from the pendulum, is that the ball is swept away the moment the pendulum.
(which in the billiard player's case is the forearm) becomes vertical and that the pendulum then proceeds just as far forward as it had previously been drawn back. Gray has a way of sending the cue much farther beyond the ball than he has previously drawn it back and in our judgment this is a mannerism and a mistake, due to an unnecessary elaboration and extension of early instructions, which in themselves were quite right. Indeed, he gives to the forward action of the cue two distinct impulses, the second beginning as the other ends. This, of course, does no harm, as the actual stroke is already completed, and it is certainly better to carry the cue even farther forward than is necessary to maintain its flow and straight alignment than not to carry it far enough.
In addition to the easy and free swing of the cue there is another vital factor, and that is the looseness or tightness with which the fingers of the player supply the necessary pivoting connection. Except in the comparatively rare instances in which a somewhat heavy handling of the cue assists in certain effects, there should be no pressure of the fingers or hand upon the cue whatever, or cue swing and stroke will be at once spoiled. Perhaps the best way to experiment in this direction is to place the object ball on the centre baulk spot and make a chalk mark at equal distances behind and before it. What has now to be done is to let the cue lie in a loop formed of the thumb and forefinger and deliver a gently swinging stroke from chalk mark to chalk mark without touching the sides of the cue with the thumb and finger at all. There will be an instantaneous reward for this class of practice and experiment in the delightfully easy and resilient way in which both balls will speed along after the minutest expenditure of energy on the part of the striker.