The Rules of Tennis
The specification for the tennis ball are codified in Appendix I of the ITF Rules of Tennis. It is probably way more detail and information than most players need or care to know. What I first took to be a subtle anachronism in the rules describing the construction of the tennis ball led me to the stunning realization that the sport we call tennis is not real tennis. Additionally, we don’t play tennis with real tennis balls.
The ball shall have a uniform outer surface consisting of a fabric cover except for the Stage 3 (Red) foam ball. If there are any seams they shall be stitchless.
ITF Rules of Tennis, USTA Friend at Court, I.a
The ITF hosts a web page on the history of tennis balls. The very first sentence in that summary distinguishes lawn tennis from real tennis. “The game of tennis (more properly known as lawn tennis) was developed in the 1870s from the game of royal or real tennis, which has been played for centuries.”2 The adjectives “real” and “royal” were added after lawn tennis was invented and popularized.
When the ITF Rules of Tennis indicate that the seams of a tennis ball are to be stitchless, essentially what is being conveyed is that tennis is not to be played with real tennis balls. You see, real tennis balls have seams with stitches.
I stumbled across a fascinating video from the Cambridge Real Tennis Club that demonstrates exactly how real tennis balls are made.
Unlike the manufacturing videos of modern tennis balls which is dominated by industrial machinery, real tennis balls are handmade. It is a delightful process that starts out by grinding wine corks which form the core of the ball. Someday I am likely to try to make one of these balls myself. Until then, I pledge to drink enough wine to supply enough cork for everyone to make their own real tennis balls. It is the least I can do for the sport.
In the meantime, I am pretty sure you can win a bar bet that the modern tennis ball is not a real tennis ball. You have my permission to use this page as evidence.
- United States Tennis Association (2021), Friend at Court: Handbook of Rules and Regulations, White Plains, NY
- The History of Tennis Balls, ITF Media Informational Page, viewed March 23, 2021.
