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Technique & Systems
The Diamond
System
How to use the table’s rail markers to build an accurate starting line for one-rail kick and bank shots—without relying on the false idea that every rebound is perfectly automatic.
“The Diamond System” is not one universal formula. It is a broad name for several methods that use the table’s rail sights as measurable references. The simplest place to begin is the one-rail mirror method: imagine the cushion as a mirror, reflect the target across it, and use the diamonds to locate the resulting aim line.
That gives you a geometric baseline. The table then tells you how much correction it needs for speed, spin, cushion response, cloth condition and the type of shot being played.
The Concept
One Name,
Several Systems
The diamonds are evenly spaced rail sights. Players use them to describe positions, compare distances and build repeatable reference tracks for bank and kick shots.
There is no single method officially called the Diamond System. Common examples include the one-rail equal-distance or mirror system, the rolling-ball two-to-one system, the Corner-5 System for multi-rail routes and the Plus System for kicks beginning from a short rail.
Mixing their scales and formulas produces bad information. This guide stays with one subject: the geometric starting line for a simple one-rail rebound.
What Was Corrected
A rule such as “label the pocket 0, place the cue ball at 20 and aim at 20 on the opposite rail” does not automatically create equal approach and rebound angles.
The correct rail contact depends on both balls’ positions and their perpendicular distances from the cushion. Matching two arbitrary numbers is not enough.
Know the Shot
Bank Shot
or Kick Shot?
Kick Shot
The Cue Ball Hits the Cushion First
Moving Ball Cue ball
After Cushion Contacts object ball
Kicks are used to reach an object ball when a direct cue-ball path is blocked.
Bank Shot
The Object Ball Hits the Cushion
Moving Ball Object ball
After Cushion Travels toward pocket
Banks require additional judgment because the cue ball can transfer cut-induced spin to the object ball.
The Baseline
The One-Rail
Mirror Method
Imagine the selected cushion as a mirror. Reflect the target contact point an equal distance behind that cushion. A straight line from the cue ball to the reflected point crosses the cushion at the geometric rebound point.
The diamonds help you measure the mirrored distance and identify the point where that line meets the rail. The method is especially useful as a starting reference for one-rail kicks played without sidespin.
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Choose the Contact Point
Decide where the cue ball should meet the object ball. For a simple legal hit, this may be the object-ball center. To pocket the object ball, use the required ghost-ball contact position instead.
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Measure Its Distance From the Cushion
Estimate the target contact point’s perpendicular distance from the chosen cushion. Use the diamonds and your cue as visual measuring tools.
Measure square to the cushion—not diagonally -
Mirror the Target Behind the Cushion
Imagine an identical point the same perpendicular distance beyond the rail. If the target is one diamond from the cushion, its mirror is one diamond behind it.
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Draw the Straight Sight Line
Sight from the cue-ball center toward the mirrored target. The location where that line crosses the cushion is the geometric aim point.
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Play a Vertical-Centerline Hit
Begin without left or right sidespin. Use a smooth speed that allows the cue ball to develop natural roll before reaching the cushion.
The mirror line is a starting reference; calibrate it to the table
The Shortcut
When the Midpoint
Really Works
If the cue ball and target contact point are the same perpendicular distance from the cushion, the rebound point lies halfway between their projected positions along that cushion.
This is the valid equal-distance shortcut. It is not the same as giving the cue ball and aim point matching numbers.
Example
Imagine the cue ball and target are both one diamond from the cushion. The cue ball projects to diamond 1 along the rail, while the target projects to diamond 5.
Because their perpendicular distances are equal, the geometric rebound point is halfway between 1 and 5: diamond 3.
If one ball is closer to the cushion than the other, the midpoint shortcut no longer applies. Use the full mirror construction instead.
Object-Ball Route
Applying the Mirror
to Bank Shots
For a one-rail bank, mirror the destination pocket across the banking cushion. Then sight a line from the object-ball center toward that imaginary pocket.
Where the sight line crosses the cushion is the idealized equal-angle bank point. The diamonds help you locate and remember it.
Unlike a cue-ball kick, a bank shot may acquire spin from the cut that sends the object ball toward the cushion. Speed also changes how deeply the ball compresses the cushion. For that reason, the mirror line is a starting reference—not a promise that the object ball will rebound like a beam of light.
The Real Table
Why the Perfect
Mirror Misses
Cushions do not behave like perfect optical mirrors. The rebound changes with the ball’s speed, spin and state of roll, as well as the table’s cushions, cloth, cleanliness and humidity.
Adjustment 01
Speed
A firm shot can compress the cushion differently from a slow rolling shot. The rebound may come shorter than the idealized line.
Practice Response
Calibrate soft, medium and firm shots separately instead of expecting one correction to fit every speed.
Adjustment 02
Sidespin
Running English generally lengthens a cue-ball rebound, while reverse English generally shortens it. The amount depends on the table and speed.
Practice Response
Build a reliable no-sidespin reference first. Add measured sidespin only when the natural path is blocked.
Adjustment 03
Cut-Induced Spin
During a bank, the cue ball can transfer spin to the object ball. That transferred spin can shorten or lengthen the bank.
Practice Response
Compare straight-on banks with cut banks and record how the rebound changes.
Adjustment 04
Table Conditions
New cloth, worn cloth, polished balls, dirt, humidity and cushion construction all influence rebound behavior.
Practice Response
Test a simple reference bank and kick before competition on an unfamiliar table.
Through the Diamond or Across From It?
For a slow-to-medium rolling cue-ball kick with the target well away from the cushion, a through-diamond reference can help account for the cue ball’s natural roll after rebound.
For faster shots or targets close to the cushion, the geometric mirror is often measured relative to the rail groove or cushion nose rather than the decorative diamond itself.
This is another reason “aim at diamond 2” can be ambiguous: some systems mean through the physical sight, while others mean the corresponding point on the cushion line.
At the Table
Four Useful
Practice Examples
Practice 01
The Straight Return Test
Cue Ball Table centerline
Aim Center diamond
Goal Return to cue tip
This checks whether you are striking the cue ball on its vertical centerline without accidental sidespin.
Practice 02
Equal-Distance Kick
Ball Distances Equal from rail
Base Aim Rail midpoint
Stroke Natural roll
Mark both ball positions so you can repeat the same layout at different speeds.
Practice 03
Unequal-Distance Kick
Ball Distances Different
Method Mirror target
Avoid Simple midpoint
This teaches why the midpoint shortcut works only when the perpendicular distances match.
Practice 04
Mirror-Line Bank
Target Mirrored pocket
Base Aim Equal-angle line
Record Actual correction
Shoot the same bank at three speeds and record whether each rebound comes short or long.
What Goes Wrong
Common
Pitfalls
Pitfall 01
Using the Midpoint Every Time
The midpoint works only when the cue ball and target are equally distant from the cushion.
The Fix
When the distances differ, mirror the target or use the full equal-distance construction.
Pitfall 02
Aiming at the Wrong Rail Reference
A diamond on the wood, a point across from the diamond in the rail groove and the cushion nose are not identical targets.
The Fix
Know whether your chosen method calls for aiming through the diamond or toward the corresponding cushion point.
Pitfall 03
Adding English Before Establishing a Baseline
Sidespin changes the rebound and hides whether the original geometry was correct.
The Fix
Begin on the cue ball’s vertical centerline and use consistent speed.
Pitfall 04
Mixing Unrelated Number Systems
The Corner-5, Plus and one-rail systems use different routes, scales and assumptions.
The Fix
Learn one system completely before borrowing numbers from another.
Study & Practice Resources
These illustrated resources explain the equal-angle, through-diamond and mirror methods in more detail, including the adjustments required for speed and target distance.
Download the Mirror-Kick Guide Download Bank & Kick Basics Explore More Diamond SystemsBuild a Better Practice Room
Banking systems become far easier to calibrate when the table is level, the lighting is even and cues are stored safely between sessions.
// Make the Table Teach You
The mirror line gives you a defensible place to begin. The next shot tells you how that particular table departs from the ideal. Mark the layout, repeat the speed and record the correction. After enough repetitions, the diamonds stop being decoration and become a map of the table you are actually playing on.
