The question as to at which ball the billiard player should look in the act of striking is as old as the game of billiards itself. What is wanted is to have a clear impression in the "mind's eye" or "brain eye" of the relative positions of cue ball, object ball, and third ball or pocket before aligning the cue and making the stroke. Turning to the great professional players, John Roberts, of late years at all events, has always laid down that the last look should be at the object ball. H. W. Stevenson, in an admirable article, has written, "The abiding rule is that the last glance of all, and the place where the sight must be resting at the moment the ball is struck, is on the object ball." Charles Dawson, in his book, puts it far more strongly than either of the professionals just mentioned, for he writes—I am quoting from memory—that "once the player has taken his aim he can remove his eye altogether from the cue ball."
Edward Diggle, too, invariably carries out Stevenson's dictum, with which the late William Cook's advice and practice were in accordance. Joseph Bennett, a player of very studied methods, advises the player (as I have done in the second edition of my little book on "Hints on Billiards" [Bell], and possibly for the same reason) to look at the cue ball. It may thus be laid down that the greatest players will always do best to look at the object ball in striking, their stance being firm as a rock and their cue delivery mechanical in its accuracy. In my own case I have made breaks of 150 (all in) looking at the cue ball last, and of 150 (under the present B.A. rules) looking at the object ball last, whilst I once played a 50 up with my eyes shut whilst I swung and delivered the cue, and made a 20 break.
If any billiard player be watched, nine times out of ten, or nineteen times out of twenty, it will be seen that the player does not align with the one eye or the other; he uses the brain "eye," and the line of vision of this mental eye represents a line drawn at right angles from a point midway between the two eyes, and when, says Dr. Doyne, I speak of this line of vision of the eye, this is what I mean. A great deal has been said about whether you should look at the object ball or the cue ball, the actual fact being that, in ordinary strokes, once you have the correct aim, which is, as I have said, a matter of brain judgment, you do not need to look at any spot in particular but take in the table generally. In billiards the use of both eyes is especially important. The game continually involves the estimation of distance and angles, and the stroke has to be made after such estimation, and it would seem an obvious inference that if the estimation of distance and angles required both eyes for each mental process involved, the further delivering of the stroke should be made in the same way. And as a matter of fact, that is nearly always the case.