The Plus System is a short-cushion-first reference for a rolling cue ball with running side spin. It is also called Plus Two, but its name does not mean that every slow shot needs two extra diamonds.
Read the short cushion first
In the cited convention, the far corner reference is 1 and each half-diamond interval adds one. The three full-diamond marks on the short cushion therefore read 3, 5 and 7. These are system values, not ordinary diamond counts.
| Distance from the corner reference | Plus scale value |
|---|---|
| 0.5 diamond | 2 |
| 1 diamond | 3 |
| 1.5 diamonds | 4 |
| 2 diamonds | 5 |
| 3 diamonds | 7 |
What the reference predicts
The chosen short-cushion value describes a reference shift along the long-cushion direction. Read the complete source diagram to identify the start and return lines; a number without those lines is not an aiming instruction.
The article linked below illustrates the system on a pool table. For carom practice, establish the corresponding corner and diamond references on your own table and check the return. Pocket geometry, cushion response and ball size are not interchangeable.
Build a calibration record
- Choose one starting position, one short-cushion target and a clearly identified return point.
- Record the starting line and which scale you used. Keep the cue level, rolling state, running side spin and pace as consistent as you can.
- Compare the intended return with the observed return. Note the direction and size of the miss rather than only whether the ball scored.
- Change only pace or side spin, repeat, and keep the setting that gives the reference return on that table. Recheck when conditions change.
Diagnose the miss
A wrong first-cushion contact is an aiming or delivery problem before it is a system adjustment. A repeatable first contact followed by a changing return calls for a check of speed, spin and table response. Changing the target and the stroke together makes those causes hard to separate.
Do not apply an automatic +2 for a soft stroke, or copy a Corner-5 number into the Plus scale. If you cannot identify the source diagram’s starting and arrival references, choose a simpler measured route before adding a formula.
A practical 3Ball comparison
Use the same ball layout for two simulated shots and alter one control. Follow the first cushion and subsequent return in the replay, then compare the direction of the change. Treat this as a model experiment, not evidence that a particular real table has been calibrated.
A three-cushion score still requires both object-ball contacts and the necessary cushion contacts before the second object ball. A successful system return by itself is not a completed carom.