The range of forward and return deformations – the change in the ball’s diameter under an increasing and decreasing load of 8.165 kg – have varied over the years, reaching their current values in 1996. The current acceptable mass range is 56.0-59.4 grams. This last changed in 2000 (from 56.7- 58.5 grams).
Additionally, do tennis balls go flat over time?
Tennis balls will go bad after about 2 weeks or 3-4 playing sessions. Unopened tennis balls are kept in a pressurized tube to help them retain bounciness and firmness, but even those will expire after two years (due to very tiny leaks).
Consequently, what do numbers on tennis balls mean?
Tennis balls have numbers printed on them so players can distinguish their balls from balls coming from another court. Most people play tennis in an area where people are playing on adjacent courts, and it is very possible that more than one court might be using the same brand and type of ball.
What is the color of tennis balls and why?
Bananas have been around far longer than tennis balls. The tennis gods picked yellow for the color of tennis balls because they thought yellow was bright enough for people to see it with ease.
So the International Tennis Federation (ITF) undertook a study that found that yellow tennis balls were easier for home viewers to see on their screens. An official 1972 ITF rule change required that all regulation balls have a uniform surface and be white or yellow in color.
The tennis balls in Grand Slams, ATP and WTA tournaments are changed after seven games and after every nine games thereafter. There are six balls in play in these events. Each ball is subject to have 105 racket or ground impacts (Lane et al., 2015).
The serve speeds you see on courtside digital displays are measured just as the ball leaves the racquet. Fortunately for returners, by the time the ball reaches them, air resistance and the friction of the court surface have diminished its speed by roughly 50 percent.
around 2 years
Pro Penn balls are very similar to Penn Tour in terms of quality and playability. The key difference is their LongPlay felt and Encore technology they are made with, which makes them one of the longest-lasting pressurized tennis balls on the market. Recently, Penn introduced a new Tribute tennis ball.
Per regulations, tennis balls are switched out after every nine games other than the first time when they’re switched out after seven games (to account for the warm-up).