Front around ball system Front Ball · line-number method
Add the front around line number, the slope and the arrival number to find a thickness and spin combination. Don’t reuse the side around scales as they are.
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Sources and diagrams reviewed: 2026-10-10. Rules of thumb are practice references for a specific diamond scale and stroke. Geometric constructions are kept separate from real trajectories, and nothing was measured on a real table. On mobile, the table stays in landscape so the directions in the text match the diagrams.
What do you read from the layout?
- Line 1: the reference line along the long axis that the first object ball sits on.
- Angle 0: the line through the two ball centers is parallel to the long rail.
- Arrival 3: three diamonds from the top corner of the opposite short rail.
Slope and correction: Extend the center line to both short rails and read the difference along the short axis. It is 1 per diamond, minus for a running angle and plus for a reverse angle. Don’t bring over the side-around 0 reference, which is parallel to the short rail.
If you’re new: what changes from the side around?
The thickness number, which divides the ball diameter into eighths, stays the same. But the direction the line numbers run, the slope spacing and the final short-rail scale change. One total does not decide one tip count and one thickness.
1. The first object ball’s line number and the last short-rail number
- 0.5·1·1.5 on the left short rail: the line number given to each yellow reference line
- 0–4 on the right short rail: arrival number, 1 for every diamond from the top corner 0
- Read which reference line the first object ball sits on. A ball between lines needs interpolation, so start by placing it on line 1.
- Read the slope of the line joining the cue ball and the first object ball as 1 per diamond on the short axis. Add it for a draw-back opposite angle; subtract it for a cutting same-side angle.
- If you place the two balls parallel to the long rail, the slope is 0. First practice arrival number 3 in this layout, then change the slope.
Read slope 0 and two diamonds in the drawings
For front cuts, read the height difference of the center line where it meets the two short rails. The direction and reference line differ from the side-cut ball system.
After reading a size of two diamonds, add −2 for a favorable-angle cut or +2 for an opposing-angle draw. Even on the same line, judge the sign again when the direction changes. The article's example of line 1.5, opposing angle +2 and arrival 2.5 gives 1.5+2+2.5=6.
2. 1 + 0 + 3 = 4, split it into thickness and spin
Line 1 + slope 0 + arrival 3 = 4
- Line number 1: the reference line the red ball sits on
- Slope 0: a parallel line joining the two balls
- Arrival number 3: the third-cushion target on the short rail
The source example starts from half-ball thickness with no English. In the cue ball drawing, no English means a top tip position with no side spin. 2 tips with 1/4 thickness is another practice combination with the same sum; it does not guarantee the same path.
Check yourself: Line 1.5, slope +2, arrival 2.5?
1.5+2+2.5=6. The source gives 2 tips + 4/8 thickness as an example. For a same-side angle with the opposite starting direction, check whether the sign of the slope changes too.
3. Short rail first: short → long → short
- After the first ball contact, check first that the cue ball goes to the first short rail. Don’t match only the calculated total and ignore the separation direction.
- The material gives no fixed power for every layout. Choose one combination and practice at a steady power; don’t change thickness and spin at the same time.
- Layouts with a large opposite angle, an object ball close to the cushion, or a strong draw need their own corrections. Don’t stretch what you learned in the basic slope-0 form to them as is.
The drawings are concept diagrams that explain the scales and the order of travel, not measured paths. Repeat with the same tip position, thickness and power, and adjust on a real table. Articles with a simulator link give a starting layout for comparison. The app’s results are not a real-world check of these rules of thumb.
Practice with the example layout
Back to the worked example and layout ↑From 1 + 0 + 3 = 4, start from a no-English 4/8 reference. Connect first object ball → short ① → long ② → 3 on the opposite short ③ → second object ball. Practice other combinations with the same sum separately.
- Point to the cue ball, the ball you hit first and the last ball, and say the cushion order.
- Repeat the same layout 5 times and record where the first cushion and the calculated target actually land.
- If the first cushion is already off, check your aim and thickness; if the first cushion is right but later ones drift, check spin and speed. Change only one thing for the next 5.
Sources and verification
- 쌈장의 3구 교실 · 앞돌리기 볼 시스템 — 라인수 이용법 — Checked the reference lines 0.5·1·1.5, the slope sign, the arrival number of 1 per diamond, and the total 4 and 6 examples.
Sources may use different diamond scales and conditions. The text notes which scale it uses and the limits of what was checked; the diagrams are our own concept drawings.