Many drills include three visual aids projected alongside the ball layout: a ghost ball, a tangent line, and a cut angle number. Not all drills include all three — they appear where relevant to the shot being practiced.

Ghost Ball

The ghost ball is a yellow circle showing exactly where the cue ball must make contact with the object ball to pocket it. It is positioned at the contact point along the shot line. If you are not already familiar with the ghost ball concept, a search for "ghost ball aiming" will turn up many useful explanations.

Cut Angle

Many drills display a number along the line connecting the cue ball to the object ball. This number is the cut angle in degrees — the angle of the shot relative to straight in.

• 0 = a straight-in shot with no cut
• 89 = an extreme thin cut, nearly parallel to the object ball

The cut angle helps you recognize and develop a feel for shot geometry as you practice.

Tangent Line

The tangent line is a yellow line extending from the center of the ghost ball. It represents the path the cue ball will take after contact if struck with no top or bottom spin — a stun shot.

Understanding the tangent line is useful for predicting and controlling cue ball position:

• If the cue ball has follow (top spin) at contact, it will travel forward of the tangent line.
• If the cue ball has draw (bottom spin) at contact, it will travel back from the tangent line.

Comparing the actual cue ball path to the tangent line is a direct way to see whether your cue ball control is producing the intended effect.