If we just bought tennis balls out of a bin or in an open box, they would lose this internal pressure. But because they come sealed, they are as pressurized as the day they were made, ready to bounce.

Tennis balls leave marks on all surfaces, but they are practically invisible to the naked eye on hard and grass courts, although on grass, chalk can sometimes fly up if a ball lands on or close to ...

Aryna Sabalenka’s ball-mark photo and the tennis dilemma of electronic line calling on clay By Charlie Eccleshare and Matthew Futterman April 21, 2025Updated April 23, 2025 21 ...