Spot on the Wall Spot-on-the-Wall · external reference point
A method of remembering a reliable reference shot by extending its aiming line to a mark outside the table. When the cue ball moves, use the same mark to find a candidate line and check the actual arrival.
Written and edited by TTBoys · How we write and check sources · Report an error
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?
- A: the cue ball’s reference position to check first.
- First aim point: where the ball goes into long ① from A.
- S: a marker off the table that you look at by extending the first aiming line.
Slope and correction: If you move the cue ball to B, the angle toward S changes too. The same S does not guarantee the same arrival, so fix the tip position and power and check the actual arrival.
First build one reference shot
The spot on the wall is not an object ball. It is a fixed mark you see when you extend your line of sight from the cue ball to the first cushion. The source explains one-, two- and three-cushion kicks in pool. Here it is adapted as practice for remembering a 3-cushion path, not presented as a new number formula in common use on full-size carom tables.
- Set up the cue ball and both object balls, and first find a reference shot that goes long → short → long and then to the object ball. Record the first-cushion spot, tip position and power that worked.
- Extend the line from the cue ball through the first aim point beyond the table. Pick a fixed mark in that direction as S. If you need to stick a marker up, ask the billiard hall first.
- Move only the cue ball to another nearby spot and look at the same S. This line is the starting point for your next attempt. Adjust while checking whether the actual first cushion and arrival match.
Layout example: A's reference line and B's candidate line
- Solid: a conceptual path showing the order of the reference shot, not a measured track.
- Yellow dashes: A's first aim line extended off the table to S
- Blue dashes: a candidate line from B toward the same S. Check where it actually lands
Coordinates are in diamonds, with the top-left corner at (0,0) and the bottom-right at (8,4). Horizontal is x and downward is y; they are not centimeters or a system's number scale. The table stays in landscape orientation on mobile too.
The diagram is a construction example that extends the line A(6,3) → first aim (3,0) to S(0,−3). Aiming at S from B(5,3) gives a first aim of (2.5,0). This calculation only finds where a straight line meets the cushion. Don't memorize S's coordinates for every table, and don't read it as B scoring just like A.
The white path explains the order long ① → short ② → long ③ and then red and yellow. It is not a simulation result that replaces the process of getting a reference shot. The blue B line is shown only up to the first aim so that you check the actual arrival yourself.
Why you fix the mark distance and the spin
Dr. Dave's analysis of 3-cushion kicks in pool explains that several aiming lines come close together roughly 0.75 to 1.5 table widths beyond the first long rail. They do not meet exactly at one point. Don't use it as a rule that “farther is always better,” or apply this distance directly to full-size international tables.
The source's multi-cushion reference uses forward roll and running English. If you change the tip position or power, or the cloth or cushions differ, the arrival changes too, so verify the mark again. In layouts where you hit an object ball first, you have to work out the post-collision departure direction separately rather than using the original cue ball.
Finding the range you can use in real play
- Shoot 5 times from A and see whether the reference repeats. If it doesn't, rebuild the reference shot before memorizing S.
- From B, with the cue ball moved slightly, shoot 5 times with the same tip position and power. Write down the first-cushion and third-cushion arrival differences separately.
- If the target ball or cushion order changes, build a new reference shot. Don't use movable things like people or chairs as marks.
Practice with the example layout
Back to the worked example and layout ↑On the white path in the picture, count long ① → short ② → long ③, then find red and yellow. Only after learning the reference shot from A, move the cue ball to B and try the blue candidate line.
- 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
- Dr. Dave · Spot-on-the-Wall — Finding one-, two- and three-cushion aiming lines with an external mark. Pool material.
- Dr. Dave · February 2011 article — Setting a reference shot, the running English and roll conditions, the 3-cushion mark distance and the limitation that there is no exact common intersection. The coordinate examples in the article were written by us.
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.