For the amateur pool player, an angled shot is easier to make than a straight shot. When the line between the cue ball and the target ball and the line between the target ball and the pocket is between about 5 degrees and 55 degrees (a moderate angle), the shooter is more likely to make the shot than if the angle is zero to 5 degrees (small or no angle) or greater than 55 degrees (a severe angle). This conclusion is based on lengthy observations of non-professional pool players.

My theory behind this observation is that the untrained eye can better visualize the point where these lines meet when there is a moderate angle between them. The point is harder to define when the lines approach one another or when the lines are at a severe angle. This is actually because of the round shape of the target ball. With a moderate angle, the area of the target ball which must be struck to sink the shot actually appears to be larger. With no angle or a small angle, the area appears smaller and thus harder to strike. With a severe angle, the area is again too small to visualize properly.

The size of the target area is actually the same in all instances, but it is the appearance of the size that allows the player the confidence to make the shot.