Using Side

Done When

You can pocket a medium cut with a tip of either side and land the cue ball in a called zone off two cushions — and can say beforehand which way the object ball will throw.

Steps

Straight-in shot, cue level, one tip of right: watch the cue ball squirt left and the object ball throw left — both small, both real.

Same shot with the cue slightly elevated: swerve brings the cue ball back toward the line. Learn your cue's balance of the two at the speed you play.

Cue ball to a cushion, no object ball: strike with running side and see the angle open; with reverse, close.

Combine: a cut where the cue ball must go three rails — pick side for the cushions, then correct the aim for the throw that side adds (inside) or cancels (a touch of outside).

Play the shot without side first, every time; add side only when the position needs it.

The Science

A tip left or right of centre spins the ball about a vertical axis. On the way to the object ball that spin does almost nothing to the cue ball's path — except squirt, a small deflection off the cue's line that is a property of the cue's front-end mass, and swerve, a curve back the other way from cloth friction if the cue is at all elevated. At the object ball it throws the object ball sideways by friction, up to a few degrees, the opposite way to the spin. At the cushion it adds to or subtracts from the along-rail speed: running side lengthens the rebound and keeps the ball alive, reverse shortens it and kills it. Players use side for the cushions and pay for it at the object ball; the skill is knowing the price.

How It Fails

Using side out of habit on shots that need none. Correcting for squirt at one speed and playing at another. Forgetting throw and missing the object ball thick. Elevating the cue for reach and getting swerve you did not plan on. Judging the cushion by a table you played last week.