Double the Rail Double the Rail / jeopsi (plate)
A path that comes back to the cushion it hit first to make up the third cushion. This page covers the jeopsi (plate) pattern, which comes in shallow with reverse English.
Written and edited by TTBoys · How we write and check sources · Report an error
Sources and diagrams reviewed: 2026-10-04. 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.
Presets are comparison examples from a physics model; they do not guarantee the formula's real-world accuracy or a point.
What do you read from the layout?
- ① First long rail A: where the ball comes in shallow.
- ② Short rail B: the direction of travel changes.
- ③ The same long rail A: it touches again at another point.
Slope and correction: ①②③ are the order of contact, not calculated values. There is no set angle factor; match the incoming direction, the remaining reverse English and the speed together.
New to this? Start here
Double the rail is a path that uses the same cushion twice. Thinking you must hit three different rails will confuse you. First, find in the next diagram whether the first and third cushions are the same long rail.
- Even if ① and ③ are the same cushion, the ball touches it again after going through ②, so there are three cushion contacts. To actually score you also have to hit both object balls.
- Trace with your finger from the white cue ball in the order ①→②→③. The diagram is a concept drawing of the path shape, not a successful layout to set up and shoot as is.
- In comparison practice, fix the first aim point and power and change the spin one step at a time. See on which cushion the path changes, and change power only when needed.
Check yourself: Long rail A → short rail B → the same long rail A: is that two cushions or three?
Three contacts. You count how many times the ball touches a cushion, not how many kinds of cushion. It is called double the rail because it comes back to the same long rail.
The path and the role of spin
- White line: the order in which the cue ball travels around three cushions
- Yellow line: an example of meeting the two object balls after the third cushion
A sketch of the worked example's ball layout and travel order. Where the ball actually lands depends on thickness, spin and speed.
Running and reverse English are named relative to the ball's direction of travel and the cushion in question. After the ball changes direction, the same side spin can act as running English on the next cushion. It doesn't mean the spin itself necessarily reverses.
Tip position and power
- On a shallow first cushion side spin has little effect on the rebound angle, and it can act strongly on the second cushion, which the ball enters more head-on.
- Find the tip position and power that leave enough reverse English for the layout. Maximum tip or a hard stroke isn't the answer for every layout.
- There are topspin and draw variants too. Don't assume every double-the-rail shot must be a follow shot or that a set follow-through length is required.
- The preset is for comparing reverse English. Change the first-cushion spot and the speed one at a time to see the conditions for coming back to the same rail.
Practice with the example layout
Back to the worked example and layout ↑In the layout example picture, the ball meets the two object balls after three cushions. Even though the first and third are the same long rail, count each one once. For a variation that hits an object ball first, compare from the line after the collision.
- 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
- japong · 더블레일 — The definition of using the same rail twice, and examples including topspin and draw.
- Dr. Dave · Bank and Kick Physics Effects — Effects of power, spin, cloth and cushions. Pool experiments, not a verification of 3-cushion number tables.
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.