Fig. 2
It should be noticed that a pocket is considerably enlarged so to speak, when there is a ball in the position shown by fig. 2, as from almost anywhere to the right of the diagonal drawn through that pocket a ball may be holed off ball 3, either directly or off cushion 2, or it may be put in without touching ball 3, which will then be left for the next stroke.
Fig. 3
Fig. 3 shows a neat stroke. Balls 2 and 3 are touching. The line passing through their centres is at right angles to the line drawn from ball 2 to the centre of the pocket. Then from any point below P Q, and even from some distance above it, a winning hazard on ball 2 is with ordinary care a certainty.
In fig. 4 a useful but rare stroke is shown. The two balls are touching or nearly touching, but are not aligned on the pocket. By playing a push shot, quite quietly, the point of the cue, never quitting ball 1, gradually directs ball 2 towards the pocket. The cue should be directed as much above P as the pocket is below it. A stroke with left-hand side will have the same effect, but to enter into reasons would be to open up the whole question of push strokes.
Diagram VI.
Fig. 4