A standardised reference shot at diamond 50 (long rail, mid-table), used to calibrate the Korean 5-and-half system to a specific table's actual cushion behaviour before relying on it in play. Every table plays slightly differently — cloth speed, cushion age, humidity all shift the numbers — and this shot is how players find out exactly how much a given table deviates from the textbook calibration.
Reference route
Reproducible table setup
A measurable starting point for this route family. The line is a practice reference, not a guaranteed scoring path.
Normalized ball coordinates
| x/L | y/W | |
|---|---|---|
| White cue ball | 0.127 | 0.500 |
| Yellow ball | 0.627 | 0.845 |
| Red ball | 0.873 | 0.500 |
Two controlled variations
- A · Change only side spin; keep the setup and pace.
- B · Change only pace; keep the setup and contact point.
Arrival tolerance target: ±35 mm
Practice protocol: 4 sets × 6 repetitions
Calculation record: Physics 3.0.0-beta · Solver 4.2.0
Physics V3 remains measurement-pending; verify the line on your own cloth and cushions.
Open this exact setup in 3ball →System Shot 50 — Setup
Cue ball at diamond 25 on your own side, mid-rail. Aim the shot at the diamond 50 reference point on the opposite long rail, striking with a repeatable, neutral setup so any deviation you observe is caused by the table, not by variation in your own stroke.
Stroke and english
Standard medium pace with neutral english — no side spin — struck at a half-ball reference contact. The entire point of this shot is consistency: the same pace, same contact, same cue elevation every single repetition, so that any difference in where the cue ball actually lands reflects the table's cushions, not your technique.
When to use it
Run this calibration test on a new table, in new conditions (temperature, humidity, a cushion rebuilt or recently replaced), or simply before a serious match on an unfamiliar table. Competitive players treat it as a five-minute investment that prevents dozens of missed system shots later in the session.
Common mistakes
An inconsistent stroke invalidates the entire calibration — if your pace or contact varies rep to rep, you can't tell whether a miss came from the table or from you. Use exactly the same pace on every repetition, and take at least 5-10 reps before drawing a conclusion; a single shot isn't enough data to separate table behaviour from normal shot variance.
Practice notes
There is no universal hit rate for this position. Repeat it under the same table conditions and compare your own accuracy, route and speed consistency over time.
Pro players who use it
No player-specific usage claim is made without a position-level match sample. Treat this as a geometry and practice pattern, not as an attributed signature shot.
Practise this position
Open it directly in 3ball — adjust ball positions, stroke, and english to match your real-table setup.
Open in 3ball →Related positions: