The slice primarily is a cut stroke. It is caused by the club engaging the ball as it crosses the intended line of flight to the hole.
In driving for an intentional slice the stance is much more open than for an ordinary drive and the ball is taken much more forward, about opposite the left instep. The right foot is nearly at a right angle to the line to the hole and the left foot almost points to the hole.
Directly the club-head leaves the ball it goes away farther from the player than the ball. It is raised outwards so that it goes up in a plane that will in the return stroke carry the club-head out beyond the line to the hole. This is the simple explanation of the intentional slice so far as regards the stroke. Of course practically all the things that I have explained in the chapter on driving take place in the slice. The main difference is in the plane of travel of the club's head in relation to the ball. This is caused principally by the alteration in stance.
The club-head in returning across the line to the hole engages the ball; and while the ball is still, as it is called, in adhesion, crosses that line, carrying the ball half flattened against its face for an appreciable distance. The ball does not leave the club until it regains its normal shape; in fact, it is regaining its normal shape that takes if off the club. While this is happening, however, the ball has flattened against the face of the club as mentioned. The face of the club is inclined back-wardly, and so the ball flattens on to it at this angle at its point of extreme compression which occurs about the middle of the full extent of the ball's travel-or roll-on the face of the club.
It may be interesting to state how this compression happens. I have never seen it stated in any book or paper, and I do not remember that I have ever before stated it myself.
We have all of us at some time seen the impression of the ball left on a club. Generally that is the clear cut brand of the compression caused by a straight hit and it gives one a good idea of the extent to which a golf ball flattens on to the club. The "picture," or impression, of a sliced ball is however quite different. The club naturally makes contact with the ball practically at a point, but it does not go on driving down a line that taken from the club through the ball would be in the plane of the ball's flight to the hole as in the plain drive. The club is crossing the line of the ball's flight. Therefore it engages the ball gradually and as it crosses it proceeds to roll it on the face of the club. The area of contact is very slight at first but it gradually broadens out until we get the full diameter of compression after which the mark narrows off by degrees until the ball leaves the club with just about the same impression as it came onto it.
The mark tells us clearly what happened. The club touched the ball very slightly at first and began to roll it. Soon the weight of the blow was felt and the ball in the course of its roll across the face of the club became fully compressed and then it gradually regained its shape as it rolled off the club.
The mark that the ball leaves on a club is an irregular stunted ellipse. The point that I want my readers to remember is, however, the angle that the ball takes in flattening on to the face of the club during its roll or movement across it. It is reasonable to assume that this angle is the chief determining factor in settling the axis of rotation of the ball.
If we admit this we see then that the slice goes away spinning from the left to the right and with the axis of rotation lying back towards the player at an angle which is roughly the same as the loft of the driver or other club with which the stroke was played.
Sometimes the slice is played as the club is going downwards and across the line. This tends to tilt the axis of spin so that the top of it inclines a little toward the player, while the angle at which it is leaning back is not appreciably altered. This point arises when we come to consider the reason for the slice being a poor runner.
A sliced ball swerves in its flight from left to right. The cause of this swerve is very simple and may be explained in a few words. On the left side-if I may use that word when speaking of a sphere-the ball has the sum of the two motions forward progression and forward revolution, for on that side the ball is spinning toward the hole. Thus, as Newton put it, the motions on that side "conspire" and they beat the contiguous air more vigorously than does the other side of the ball, where the motion of the spin is away from the hole. Every projectile naturally seeks the line of least resistance. It follows then that the ball edges over to that side whereon there is least friction, the backward-spinning side. This is a short and simple explanation of why the golf ball swerves in its flight.
Comparatively few players could explain what causes a slice and the resultant swerve which is so often disastrous. Is it likely that if one does not know how one is offending that one can take effectual steps to stop the offense? It seems reasonable to think that a clear idea of how the slice is produced must help any one who wants to do it, or any one who is doing it and desires ardently not to do it. The golf stroke makes such an inexorable demand for accuracy that it seems to me that if one desires to excel, particularly if one has taken to the game late in life, one's best chance for success lies in knowing all there is to be known about the game outside of playing the strokes. Surely, if one brings to one's aid this knowledge, which cannot possibly, when sanely used, hamper execution in any way, one must have a better chance of success than he who insists on groping in the dark in the pathetic idea that he cannot take advantage of the accumulated work of those who have gone before him.
Golf really is not a game calling for a vast amount of intellect. If it were so, we should not see the men who are supreme at it where they are. None knows that better than they themselves. They have got where they are by a lifetime of imitation, by learning through the eye - probably the best way, too, if one has time enough, and lacks either the desire or the power to use some gray matter with one's strokes.