The fuzz on tennis balls is to slow the balls down.
Tennis balls are made to exacting standards so players have a relatively decent chance of hitting them.
The fuzz makes the ball softer and less bouncy and increases wind resistance.
In addition, the fuzz adds to a player’s racket control because the strings hold onto the surface of the ball longer.
What’s the fuzz made of? Felt cut into two shapes that look like peanuts or figure-eights.
When glued together, they cover the hollow rubber core of the ball completely and give it that distinctive look.