# What Do The Numbers On Tennis Balls Mean?

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Have you ever wondered what those numbers on tennis balls mean? If you’re a tennis player, you should know! Check out this blog post to find out.

## The three main numbers

There are three main numbers on a tennis ball: the diameter, the deformation, and the bounce. The diameter of a tennis ball is 2.57 inches. The deformation of a tennis ball is the amount the ball can be compressed and still return to its original shape. The bounce of a tennis ball is measured by how high the ball bounces.

### The first number

The first number on a tennis ball canister is the most important one. It indicates how much bounce the ball will have. A higher number means more bounce. The amount of bounce a ball has is important because it affects both how high the ball will bounce and how fast it will come off your racket when you hit it. If you want to hit the ball hard, you need a ball with less bounce so it doesn’t fly up too high and slow down when it hits your racket.

### The second number

The second number on a tennis ball corresponds to the amount of bounce the ball has. The scale for this measurement goes from 1 to 4, with 1 being the minimum amount of bounce and 4 having the highest.

### The third number

The third number on a tennis ball can be confusing. It doesnâ€™t actually have anything to do with the size of the ball. The number is actually a measure of the amount of bounce the ball will have. A higher number means the ball will bounce higher.

This number is also known as the Coefficient of Restitution, or COR. It is a measurement of how much energy the ball transfers to the surface when it bounces. The more energy that is transferred, the higher the ball will bounce.

The International Tennis Federation has set a limit on how high this number can be. For tennis balls that are used in professional matches, the COR can be no higher than 0.86. That means that when these balls are dropped from a height of 100 inches, they should bounce up to 86 inches high.

The USTA has set a similar limit for tennis balls that are used in USTA-sanctioned matches. These balls must have a COR of between 0.83 and 0.86.

Balls with a lower COR will lose energy when they hit the ground and will not bounce as high. These balls are often used by beginner and recreational players who are still learning how to hit the ball correctly.

## The other numbers

In addition to the “ONE” or “two” on tennis balls, there are also letters and numbers on them. These other markings help to identify the balls clearly and also provide some identifying information. The numbers on tennis balls help to indicate the ball’s weight, while the letters identify the ball’s manufacturer.

### The fourth number

The fourth number is the date of manufacture. It is a two digit number, with the first number being the last digit of the year, and the second number being the week of manufacture. For example, if a ball has the code “42,” it was made in the 42nd week of either 2002 or 2012.

### The fifth number

On a tennis ball, the fifth and final number indicates how long the ball has been stored. For example, a ball with the coding “2 1 2 4 5” would have been made in 2021, stored for one year and then sold in 2024. The number goes up to 9, after which the ball is considered too old to sell.

## How to remember the numbers

It can be pretty confusing trying to remember what all the numbers on tennis balls mean. Do they refer to the size of the ball? The weight? The bounce? Luckily, it’s not quite that complicated. The numbers on tennis balls actually refer to the amount of money that goes into making the ball.

### A mnemonic device

One way to remember the numbers is to use a mnemonic device. This is a tool that helps you remember information by linking it to something else that is more easily remembered. For example, you could link the numbers on tennis balls to the planets in our solar system. The first planet from the sun is Mercury, which corresponds to the number one. The second planet is Venus, which corresponds to the number two, and so on.