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I hear a lot of confusion around the issue of the size of the cue ball versus the object balls. And suppose you often play at public pool tables, particularly in bars, leisure centres or gaming arcades. In that case, you may think that the cue ball looks slightly different from other balls. So, in this article, I answer the question of “Is the cue ball bigger or smaller than the other balls?”

In almost every game of pool, the cue ball is usually the same size and weight as the object balls. This is because even a tiny difference in the size of the ball can affect the dynamics of the game. However, some table types and playing styles vary on a smaller or larger ball.

Standard billiard ball sizes

Before looking at why certain billiard balls may have different sizes, it is essential to understand how ball sizes differ in the various billiard games that are common around the world. Below is are typical ball diameters for the most popular games, from largest to smallest.

Carromi – 2 7/16″ (61.5mm)

Russian Pyramid / Kaysa – 2 11/16″ (68mm)

Snooker – 2 1/15 inches (52.5mm)

American Pool – 2 ¼” (57.15mm)

British Pool or Blackball Pool: 2″ (51mm).

The typical ball size for each game depends mainly on the size of the table and the nature of the game. For example, Blackball is usually played on six or 7-foot tables with smaller pockets, so smaller pay is used. 

For most games of Blackball, the object balls and cue balls are always the exact sizes, at least on standard tables. Only in American billiards and Blackball can you find balls with a different diameter than the cue balls. 

Because of this particular type of billiards many of us are starting to play – the coin table.

Why does the size of the billiard balls differ at the coin-operated tables?

Coin-operated pool tables – often called “bar boxes” – are equipped with internal ball return mechanisms that return the balls to the pool ball cover when they hit the pockets. The cue balls on many coin-operated tables are made of a different size. They don’t mix with object balls trap if a player scratches them (accidentally hits the ball into the pocket).

If a billiard ball went straight into the ball trap every time someone scratched it, it basically would mean game over – you’d have to score more quarters to free the balls and start all over again. You’d get tired of that quickly.

Manufacturers have realised this and have developed tables with ball return mechanisms that can recognise or differentiate the cue ball and direct it a different way to the table head. 

Keeping the billiard ball in play

On most older tables, this was accomplished by using a slightly larger cue ball – usually 2 1/4 inches in diameter – and placing a separator or “ball shunt” at the point where the ball return tracks come together. The shunt is placed high enough for the 2 ¼” object balls to pass under it. When a billiard ball gets too large, the shunt blocks it and directs it along a separate path that leads to a small compartment at the head of the table.

On British coin-operated tables, the method of separating the balls is reversed: the smaller billiard ball – usually 1 ⅞” in diameter – can pass through the smaller opening, while the two-inch balls pass further inside the ball trap.

However, most modern coin-operated pool tables no longer use this design – it has largely been abandoned in favor of more sophisticated ball recognition methods that produce balls of uniform size. But these old tables are still used, especially in bars and basements.

And in British billiards most players still use smaller balls, even on tables without mechanical ball return. The tradition lives on!

Weighted billiard balls

Some coin-operated tables use a weight-driven ball separation mechanism that recognises and retrieves the bcue balls. The billiard balls on such tables have a standard diameter of 2 ¼ inches but typically weigh about 6.7 ounces. In contrast, standard billiard balls weigh 5.5 or 6 ounces.

Worn balls and mismatched sets

Another possible reason why you may end up with an undersized or oversized cue ball is mixing balls from two (or more) different sets. This often happens in bars and leisure centres, where the equipment may have been donated or bought second-hand (and probably wasn’t originally of the best quality). Still, it also happens in some pool halls. 

When billiard balls become worn, damaged or lost, which is common in public venues, management may replace them individually rather than replace the whole set. There is usually nothing wrong with this, as most billiard balls are almost the same size and weight. But occasionally, an old, oversized billiard ball that has been sitting in storage for a few decades may end up in the set.

Similarly, old balls that have been used a lot and have worn out maybe a bit lighter than the new replacement balls added to the set.

We know that some billiard balls are slightly different sizes, although this is quite rare (unless you live in England). But how significant can the difference be in fractions of an inch? It turns out that it is pretty large.

How does Cue ball size affect the game?

Using a cue ball that is even slightly different in size to the subject ball can significantly impact the game, primarily due to the difference in mass and the change in contact point. English shots will be easier or harder depending on the relative size of the billiard ball and the direction of spin.

Large/heavy billiard ball

With a large and/or heavy ball, stun shots, stop shots and draws will require a little more backspin as the extra mass will cause the cue ball to move forward. At the same time, less topspin will be needed on follow shots as the massive billiard ball will naturally continue to move forward after contact with the object ball. Additionally, a heavier cue ball has less effect of deflecting out of the aiming line.

Smaller/lighter billiard ball

When using a smaller and/or lighter cue ball, the reverse is true: less spin is required for stuns, stops and draws, while more topspin is necessary for follow shots. A lighter ball will also “squirt” more when sidespin is used.

Vertical Bounce.

An even bigger problem is that mismatched balls tend to bounce slightly off the table when they hit each other. This is because the point of contact will be slightly above or below the equator, which means that some of the force of motion will act vertically, not just horizontally. When the ball moves even slightly away from the surface of the table, it can affect accuracy.

Rail shots

Balls of different sizes can also make it difficult to hit the rail directly because the point of contact will be a little farther from the edge of the cushion (or farther inward with a smaller ball). When the cue ball strikes the cushion, it exerts a lateral force on it, causing it to bounce off the cushion.

To sum up

In most cases, different-sized cue balls are not very common, unless you live in the UK or Australia where Blackball is popular and smaller regular cue balls are still common. However, this does happen, especially in older bar boxes and second-hand billiard tables.

If you’re determined to use only uniform balls, your best bet is to find a bar with a new coin-operated table with a magnetic or optical-ball return system – or find a more professional billiard hall. Or, of course, you can buy your own table and set of billiard balls.