A class of shot that can be profitably practised on the baulk line is the short range screw stroke. Place the red ball on the centre spot and the cue ball on the circumference of the D in a direct line behind. Strike low, aiming exactly half-ball, and the cue ball will travel precisely along the baulk line to the side cushion. This is what is called a right-angle screw, and it is difficult, no matter how hard the stroke, to screw more than this with a halfball contact. Aim rather fuller than half-ball and the side cushion will be struck between the baulk line and the pocket, aim mid-way between edge and centre, and the cue ball will enter the corner pocket; aim nearly full and the bottom cushion will be struck between its centre and the pocket; aim dead full, and the ball will come straight back to the centre of the bottom cushion. Finer than half-ball contacts can now be practised from the same position. Aim a quarter of an inch fine and the side cushion will be struck above the baulk line; aim half an inch fine and the side cushion will be struck still higher; aim three-quarters of an inch fine and the point reached will be higher still, but not quite so high as the middle pocket which is a half-ball shot with top from the position described.
In making all classes of screw strokes the essential thing to do is to drive the cue well past the spot on which the object ball lies. A screw stroke is really a reversed "follow," or "top," stroke, and the cue should flow through the ball in precisely the same way, except that, at the very moment of contact—but not before—it may be pinched between the thumb and forefinger. Splendid way can be got on the ball by this method and it is a great pleasure, in a straight drawback, to see the cue ball ripple towards one full of life and motion.