Do not withdraw the cue; it is an awkward habit many persons have acquired. The limit of the swing of the cue is governed by the strength of the stroke. Full instructions in regard to the cue and its delivery have already been given.
Bringing C beneath the diagram, we have the “English” stroke, with the cue delivered at ½ right of centre, which imparts to the cue-ball a perpendicular axis. A variation to the slightest degree in twist makes a difference in the direction of the cue-ball, which can only be appreciated by those who have studied it carefully.
A player, when instructed to deliver a ⅛ cue-ball, for instance, will disregard the direction and deliver a ¼ or even a ½ ball, apparently unconscious or careless of the value of the change. When it is understood that a cue-ball may be made to carom upon a ball placed _anywhere_ upon the bed of the table by the application of the proper degree of twist, then the player will recognize the necessity or advisability of so fixing the various degrees in his mind as to have them always ready for use. A twist secures, of course, a _false_ angle, and is used generally when the natural angle will not accomplish the result desired, and again, often is employed to control the object-ball.
The velocity of the cue-ball in the twist-stroke is governed by the divergence from the centre at which delivery of cue is made. There is a method in employing twist which is effective, that of combining it with the division of the object- and cue-balls, giving an exact line of aim to be had in no other way. When the twist is applied to that side of the cue-ball coming in contact with the object-ball, the aim will be more positive, as the cue covers the exact line of aim through the two balls.
The effect of the twist may be marked by placing the cue-ball upon its spot, and playing the cue-ball, hit in its centre, at the left side cushion, at an angle of 45°. The ball in its rebound taking a natural angle, traverses a line corresponding to its original line of departure from the cue. Impart right-hand English and the angle grows obtuse; increase the twist and the angle widens accordingly, and it grows until the extreme angle is reached through application of excessive twist.