Carom Shots
Using one object ball to redirect the cue ball or another ball toward a pocket.
What a carom is
A carom shot uses contact with one ball to change the course of another ball, most commonly letting the cue ball glance off a "helper" object ball on its way to pocketing the intended target, or using one object ball to nudge a second object ball into the pocket. Rather than avoiding a ball in the way, a carom shot deliberately uses it.
Judging the deflection angle
When the cue ball caroms off an object ball it is not aimed to pocket, its path bends by an amount that depends on how full or thin that contact is — a fuller hit deflects the cue ball less, a thinner hit deflects it more, similar to the throw effect seen on any glancing contact. Estimating this deflection accurately takes practice, since it is easy to misjudge how much a "traffic" ball will alter the cue ball's course.
Caroms as both offense and position tools
Caroms are not only used to pocket a ball you could not otherwise reach directly; they are also a position tool, letting a controlled deflection off a nearby ball redirect the cue ball toward good shape for the next shot. Recognizing a carom opportunity often turns an apparently blocked or awkward layout into a straightforward runout.