English (Sidespin) Guide

Learn how left and right english changes the cue ball's path off rails, understand deflection and squirt, and discover when sidespin helps versus when it hurts your game.

What is English in Pool?

English, also called sidespin, is any horizontal spin applied to the cue ball by striking it to the left or right of its vertical center axis. When you hit the cue ball on its left side, it spins clockwise when viewed from above (left english). Striking the right side produces counterclockwise spin (right english). This lateral rotation does not change the cue ball's initial direction of travel, but it dramatically affects what happens when the ball contacts a rail.

The term "english" is used primarily in American pool. In British snooker, the same concept is called "side." Regardless of the name, the physics are identical. The spinning ball grips the rubber cushion differently than a ball with no sidespin, which alters the rebound angle in predictable ways once you understand the mechanics.

English has no effect on the cue ball's path to the object ball on a straight shot in ideal conditions. The ball travels forward in the same direction whether it is spinning laterally or not. However, in practice, applying english introduces two complications: deflection (also called squirt) at the moment of the stroke, and swerve (curve) over longer distances. Both must be accounted for when aiming with english.

Many intermediate players avoid english because it adds variables that make shots harder to predict. This is reasonable for straight-in pocketing situations. But for position play, kick shots, and safety exchanges, english is indispensable. It gives you access to cue ball paths that are physically impossible without sidespin, expanding your options on every single shot.

How Sidespin Changes Rail Angle

When a cue ball with no spin hits a rail, it rebounds at approximately the same angle it arrived (angle of incidence roughly equals angle of reflection, adjusted for friction and cushion compression). This is the natural rebound angle, and it is what the diamond system predicts.

Running english spins the ball in the same direction it will naturally rebound. If you are hitting the right rail and want the ball to come off that rail moving toward the left, running english is left spin. The spin grips the cushion rubber and accelerates the ball along the rail, making it rebound further down-table than the natural angle would suggest. Running english opens up the angle, sending the ball on a wider, longer path off the rail.

Reverse english (also called check english or hold-up english) spins the ball opposite to the natural rebound direction. It fights the cushion, causing the ball to slow along the rail and rebound at a shorter, tighter angle than natural. The ball comes off the rail closer to where it went in. This is useful when you want the cue ball to stay in a smaller area after rail contact rather than traveling across the table.

The amount of angle change depends on how much spin you apply and how fast the ball is traveling when it contacts the rail. More spin at lower speed produces maximum effect because the ball spends more time in contact with the rubber, allowing the spin to grip and redirect. A hard shot with spin has less angle change because the ball compresses the cushion and leaves before the spin fully takes effect.

On multi-rail kicks, english effects compound. Running english on the first rail makes the ball arrive at the second rail with a different angle and still carrying some spin, which further opens the rebound. Two rails with running english can send the ball to positions that seem geometrically impossible when you first see them executed. This compounding effect is why three-cushion billiards players rely so heavily on english.

Deflection and Squirt

Deflection (called squirt in many instructional materials) is the cue ball's initial deviation from the aimed line when english is applied. When you strike the cue ball to the right of center, the ball deflects slightly to the left of where your cue is pointing. Strike left of center, and the ball deflects to the right. This happens because the off-center hit imparts a sideways force at the moment of tip contact.

The amount of deflection depends on your cue's characteristics, primarily the shaft stiffness and end-mass. Low-deflection shafts (also called low-squirt shafts) are engineered with lighter, stiffer tip ends that minimize this effect. Standard maple shafts produce more deflection. Knowing your cue's deflection profile is essential for accurate play with english.

To compensate for deflection, you must aim slightly opposite to the english direction. If you are applying right english (which deflects the ball left), aim a hair to the right of your intended line. The amount of compensation varies by cue, by how much english you apply, and by the distance to the object ball. More english means more deflection, which means more compensation.

Swerve is a separate phenomenon that occurs over distance. A cue ball struck with english and a slightly elevated cue (which is nearly always the case due to bridge height) will curve during its travel. The curve direction depends on the english: right english with an elevated cue causes the ball to curve to the right after initially deflecting left. On short shots, swerve is negligible. On long shots, it can bring the ball back toward the original aim line or even past it.

The interaction between deflection and swerve is what makes english difficult for many players. On short shots, you only deal with deflection. On medium shots, deflection and swerve partially cancel each other. On very long shots, swerve can dominate. Our interactive tool visualizes these effects so you can see how distance changes the equation and develop intuition for how much compensation different situations require.

When to Use English

Use running english on kick shots and bank shots when you need to widen the rebound angle. If the diamond system tells you the natural path falls short of your target, running english extends it. This is the most common application in game situations: you are kicking at a ball, the natural one-rail path does not quite reach, so you add running english to push the cue ball further along the rail.

Use reverse english when you want to control the cue ball after pocketing a ball near a rail. If you pot a ball in the side pocket and need the cue ball to stay on the near half of the table, reverse english checks its speed off the nearby rail and keeps it from traveling too far. Without it, the cue ball might drift across the table into a poor position for the next shot.

Use english for position play when vertical spin alone cannot get you where you need to be. If you are cutting a ball to the right and need the cue ball to come off the bottom rail heading left, right english on the cue ball will open up that rebound and send it where follow or draw alone cannot reach. English adds a lateral dimension to your position options.

Avoid english when pocketing is difficult and you cannot afford deflection error. Thin cuts at long distance with english are among the hardest shots in pool because you must simultaneously compensate for the cut angle, the deflection, and any swerve over the long distance. In these cases, pocket the ball with center-ball and accept the resulting position, even if it is imperfect.

Avoid english when you do not have a specific reason to use it. Recreational players often spin the cue ball habitually, adding english out of feel or style rather than purpose. Every bit of unnecessary english introduces deflection error without a corresponding position benefit. Disciplined players use center ball as their default and only add english when the position route demands it.

The progression for most improving players is: first learn to pocket balls with center ball reliably. Then add follow and draw for vertical position control. Then introduce english for rail-contact position routes and kick shots. Each layer builds on the previous one. Rushing to english before mastering center-ball accuracy creates bad habits that are difficult to undo later.