Sliding
The contact or state: The bottom point moves relative to the cloth.
Sliding can include backspin, overspin, or too little forward rotation for the travel speed. Cloth friction changes both speed and rotation.
Read the lesson →A little influence.
Know where it goes.
The cue starts it. The cloth changes it. The next contact decides what happens. Learn each part, then put them together.
1 · Cue to cue ball
Start at the tip.
Align the cue, choose the contact, and deliver a repeatable stroke. High and low control forward/back rotation; side adds English. Diagonal contacts combine them.
Cue speed affects impulse and spin. A bigger offset also changes the transfer. Elevation tilts the force and spin axes. Chalk and a clean tip matter; a heroic edge contact is a poor substitute for a repeatable one.
Cue alignment, contact & strength →Name the state, not just the clock position
All the usual ways to turn.
Stun at contact
The contact or state: No top or bottom rotation at object-ball contact.
A full hit can stop near contact. A cut initially sends the cue ball toward the tangent line. Stun can coexist with sidespin.
Read the lesson →Natural roll
The contact or state: Forward rotation matches travel: the bottom point does not slide.
Cloth can create this state after a center hit, or after initial backspin has worn off. It affects the cue-ball route after a cut.
Read the lesson →Topspin / follow
The contact or state: A high contact supplies forward rotation; cloth changes it on the way.
Forward rotation remaining at object-ball contact drives follow. Extra spin beyond natural roll is overspin, not a new aiming rule.
Read the lesson →Backspin / draw
The contact or state: Low contact starts rotation against the direction of travel.
Backspin remaining at object-ball contact can bring the cue ball back. Low contact alone does not guarantee draw.
Read the lesson →Left & right English
The contact or state: Side offset, named from the shooter looking along the cue.
Vertical-axis rotation affects aim through squirt/swerve, friction at ball contact, and the later cushion response.
Read the lesson →High side / low side
The contact or state: Combine one side offset with high or low contact.
Forward/backward rotation and sidespin act together. Two offsets share the available contact margin; the corners of a square are not safe extremes.
Read the lesson →Inside & outside
The contact or state: Names for sidespin relative to the object-ball cut.
Inside is toward the cut; outside is away. The gearing amount of outside spin can reduce throw. Arbitrary extra outside spin can add throw again.
Read the lesson →Running & reverse
The contact or state: Names for sidespin at a particular cushion and approach.
Running tends to lengthen a rebound; reverse checks it. The same left or right setting can take a different name at another cushion.
Read the lesson →Elevated-cue curve, massé, and jump are a separate step. Raising the cue changes the spin axis and can curve the ball; full massé and airborne motion need separate instruction and venue permission. The grounded lab covers modest elevation, not those complete specialty shots.
Two balls. Two different stories.
The cue ball.
Backspin can wear away into stun, then roll. On a full hit, stun can stop; remaining backspin can draw; forward roll can follow. On a cut, the initial tangent and the later cloth-driven curve are different parts of the route.
Follow the changing spin →The object ball.
Contact friction can throw it away from the line of centers and transfer a little spin. On a near-full hit with side, the transferred side is opposite the cue ball’s. Cut contact can generate spin without intentional English.
Throw, transfer & departure →Keep squirt, swerve, and throw distinct: initial cue-ball deflection, later cue-ball curvature, and a change in the struck ball’s direction. More side does not guarantee more useful throw.
3 · Cue ball to cushionA different kind
A different kind
of contact.
A ball can move away. A cushion pushes back, grips, and changes rotation. Its raised nose, rubber, approach angle, speed, and the spin arriving there all affect the rebound.
Running and reverse describe that cushion contact. Inside and outside describe an object-ball cut. A bank sends the object ball to a cushion; a kick sends the cue ball. Keep those arrangements separate.
Read the cushion reaction →Compare one thing at a time.
- Choose the cushion-only setup in the 3D lab.
- Hold line and cue speed. Compare center, left, and right.
- Hold the side. Compare high and low.
- Change the approach angle, then name running/reverse again.
The same experiment on your table is the calibration. The model supplies a useful question, not a guaranteed landing diamond.
The 3D shot lab.
See the cue line and tip height. Change the stroke. Step through the contact. Use the cue-ball close-up to read rotation, then pull back to the whole table.
Want to arrange your own shot? Practice Table →
Cue alignment · contact · pace · consequences
Grounded physics studySet it up. See what follows.
Change the cue line, tip contact, elevation, and stroke strength. The motion is recalculated.
A straight-in cue ball and one object ball. Compare low, center, and high contact while holding the line.
Still setup. The 3D study adds the cue, alignment lines, spin, contacts, and playback.
3D is unavailable here. The setup, lesson, and text explanations remain available.
Dashed white: cue aim. Muted dashed: prepared line. Solid white: cue-ball track; gold/red: object balls. Wire sphere: cue-ball position at modeled ball contact. Contact angles are measured from the line of centers or cushion normal.
Ready. Playback starts only when requested.
Launch speed —Tip impulse —Cue-ball speed —Spin at this frame —
Contact sequence & results
Cue speed changes impulse, spin, and travel. Playback speed only changes how fast you watch. The rendered fore-end shows the cue’s alignment and contact height.
Model & cue-specific calibration
Positive is counterclockwise in the overhead table view. Start at 0° unless you have a measured value for this cue and contact. Squirt is cue-specific; no universal degrees-per-tip value is assumed.
Nominal 2.54 × 1.27 m cloth, 57.15 mm balls; cue/ball masses 0.54/0.17 kg. Sliding/rolling friction 0.20/0.01, ball restitution 0.95, cushion restitution 0.78. Cushion friction 0.18 is a provisional model setting. Cloth, ball cleanliness, cushion rubber, and pockets vary.
Solid-sphere impulse, cloth slip/roll, ball friction, and a raised cushion nose are modeled. Balls stay on the cloth; jump, full massé, pocket jaws, cushion compression, and cue-shaft flexibility are not simulated. Strength is not a measured force in newtons.
Watch the cue ball after contact and the object ball toward the middle pocket. The cue ball may draw, stop near contact, or follow.
Learn it in parts.
1. Cue to cue ball
Alignment, tip offset, cue speed, elevation, chalk, and a clean delivery.
2. Cloth to collision
Track sliding, backspin decay, natural roll, and the state that actually arrives.
3. Cue ball to object ball
Separate cue-ball departure from object-ball throw and transferred spin.
4. Cue ball to cushion
Different contact, different friction. Name the cushion and approach first.
Now give it an audience.
Three prepared 3D studies with a real cue line, adjustable contact and strength, ball collisions, and cushion response. They remain candidates until practiced on an actual table.
A Repeatable Demonstration
Controlled draw demonstration
Open this 3D setup →A Simple Combination
Prepared combination
Open this 3D setup →Try a One-Rail Bank
Prepared object-ball bank · 3D setup
Open this 3D setup →Keep the model honest.
These are nominal, grounded rigid-ball studies. Cloth slip/roll, impulse, contact friction, and a raised cushion nose are included. Cue-specific squirt can be entered as a measured initial deflection; it is not guessed from a universal offset coefficient. Pocket jaws, complete cushion deformation, airborne motion, and full massé are outside this model.
For practice, change one input, make a prediction, and compare it with your table. Use the spin practice progression and keep the actual result in your private account notebook.