Visual Academy: Aiming & Spin

Fractional aiming

A full hit aligns the centers. A half-ball hit aims the cue-ball center toward the visible object-ball edge. A thinner overlap produces a larger cut. Fraction means overlapping width as seen along the incoming line, not overlapping area. Equal-sized balls obey cut angle = arcsin(1 − overlap), before throw.

These are geometric references, not guaranteed potting lines. Throw, perspective, ball size and delivery change the real shot.

The cue-tip clock

The tip clock describes WHERE you hit the cue ball, not the cut angle. Twelve adds forward rotation, six adds backspin, three adds right sidespin, and nine adds left sidespin. Diagonal positions combine vertical and side rotation.

A clock position specifies direction, not tip offset. Begin close to center; never use the ball edge as a strike target.

The cut-angle clock

One hour on a clock is 30°. With the incoming line at twelve, twelve-thirty is 15°, one is 30°, one-thirty is 45°, two is 60°, two-thirty is 75°, and three is 90°. Mirror the clock for cuts to the other side.

Three-quarter is about 14.5°, not exactly 15°; quarter-ball is about 48.6°, not 45°. A 90° grazing limit has no useful full contact.

Tip offset and the miscue boundary

Tip offset is the distance from the cue-ball center to the contact point, viewed from behind the cue. Half the ball radius is a rough outer guide for substantial spin, not half the diameter. With combined side and vertical spin, the total radial offset matters.

Chalk, tip curvature, tip condition, elevation and delivery affect miscues. Stay comfortably inside the guide and never deliberately chase its edge.

Squirt versus swerve

Squirt is the initial deflection opposite the side-tip offset. Swerve is the later curve associated with spin, cloth contact and cue elevation. With left sidespin, the cue ball initially deflects right and can curve back left. Right sidespin mirrors this.

Net aim depends on distance, speed, elevation, cloth and shaft. Slower travel gives swerve more time; never compensate by one universal angle.

Ball-hit fractions and exact angles

The cut is the angle between incoming cue-ball travel and outgoing object-ball travel. For equal balls without throw, the line joining their centers at contact determines the object-ball direction. Smaller overlap increases the angle.

Do not reuse the numerical throw tables from the screenshots as universal corrections. Their conditions are not fully specified.

Ghost-ball aiming

Choose the pocket entry point and draw a line from it through the object-ball center. Imagine an equal-sized cue ball touching the object ball on the far side of that line. Its center is one full ball diameter from the object center. Aim your real cue-ball center toward this ghost center.

The object’s contact point is not the cue-ball center’s aim point. Ghost-ball geometry does not automatically compensate for throw.

Collision-induced throw

When balls slide sideways against each other at contact, friction can alter the object-ball direction. This is collision-induced throw (CIT). For stun shots, throw is often greatest around a half-ball cut; at slower speeds the maximum can shift toward thinner cuts. Spin-induced throw is a related but distinct effect.

Throw depends on cut, speed, spin and ball cleanliness. Faster cuts and rolling/drawing contact generally reduce CIT compared with slow stun, but no fixed degree correction works everywhere. Do not add sidespin blindly.

Follow, draw, stun and stop

Follow means forward rotation at impact; draw means backspin at impact. Stun means little forward/back rotation at impact. A stop shot is the full-hit result of stun. Center-ball contact is a tip location, not a guarantee of stun: cloth friction can turn a sliding ball into a rolling one before contact.

A low hit may arrive as stun or roll if backspin wears off. On a cut, a stunned cue ball travels along the tangent line rather than stopping dead.

Plan the cue-ball route

Drawn on a 2:1 regulation bed with true 2¼-inch balls. Routes are conceptual; read the conditional angle rules below.

With equal balls and stun at contact, the cue ball initially leaves along the tangent line, approximately 90° to the object-ball direction. For a naturally rolling cue ball and roughly quarter-to-three-quarter hits, the departure is often about 30° from the incoming cue-ball direction. These angles use different reference lines.

Thirty degrees is an approximation, not a rule for all cuts. Full hits, very thin hits, speed, draw/follow and real-table effects change the route. Choose a landing zone away from pockets and blockers before getting down.