BILLIARDS LAB / PERSONAL STUDY
Set the shot. Change one thing. See what happens.
THE GHOST-BALL METHOD
The white ring is the ghost ball. Send the cue-ball center toward that ring to deliver the object ball along the gold line.
GUIDED PRACTICE / WHY SPIN MAKES YOU MISS
Play this shot with no side spin. Notice the clean approach to the ghost ball. We will keep this exact layout for the next step.
Your reference shot is ready.
Teaching model · No account data or tracking · Settings stay in this tab
YOUR TABLE GUIDE
Drag either ball. Or select Cue / Object and tap the felt. Pick a pocket, set the cut, then play the shot. Rewind brings the balls back without changing your setup.
A naturally rolling cue ball typically leaves roughly 30° from its incoming direction for cuts around 14–49°. The ideal rolling model peaks near 34°. The purple ray is a 30° reference; the green path is the model. A stun shot follows the tangent line instead.
Use the vertical slider or drag the contact dot. High tip adds forward spin; low tip adds backspin. A low hit can become stun or natural roll over a long distance. The dot shows the strike location; the impact-state readout shows what spin survives at contact. Both balls keep moving independently after a pocket or cushion contact.
Squirt first sends the cue ball away from the tip side. An elevated cue can make it swerve back. Contact friction can also throw the object ball. Right spin and left spin refer to your view behind the cue, not left and right on the screen.
Diamond numbers are evenly spaced rail landmarks (long rail 0–8, short rail 0–4). At zero spin the model reflects equally at the effective cushion line. Spin changes the departure angle. Pockets end the path. The object ball is hidden in this workspace.
Choose Kick shots to keep the object ball on the table while aiming in any direction. The Aim tool sets the direction from the cue-ball center to where you click; it does not move either ball. Use exact degrees or 0.1° buttons for small changes. First contact after one or more cushions counts as a kick contact. A direct hit, a miss, and a cue-ball pocket are reported separately. Reset layout loads an illustrative one-rail setup.
This is a deterministic teaching aid. Squirt, swerve, spin-induced throw and cushion spin use illustrative coefficients; they are not fitted to your cue or table. Cut-induced throw, ball-to-ball spin transfer, jaw contacts and full sliding/friction dynamics are omitted. Pocketing is an approximate mouth check. Pace changes modeled swerve, throw and travel length. In rail mode it changes launch speed and travel length; cushion spin remains an illustrative response. Each ball has its own time track and continues until it stops or pockets. Secondary ball-to-ball collisions after the first impact are not modeled.
Vertical tip position sets initial forward or backward spin. Sliding friction changes that spin on the way to the object ball, then curves the cue-ball path after impact. The 30° study also offers ideal Rolling and Stun presets; adjusting the tip returns to Auto. The contact dot is limited to a half-radius disk, shared by side and vertical offsets. Aim adjustment rotates the cue line; positive turns it counterclockwise in top view. Get your real-table center-ball reference first, then use small amounts of spin and compare at a consistent pace.
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