For most club players, a ball lasts about 2-3 hours of hitting. You can use it longer, but it will lose bounce.
To give you an idea of how long a ball lasts for top players, intercollegiate players use a new ball every match. Pros are allowed to switch to a new ball after only 2 games.
The ball will appear smooth once its bounce starts to fade, and the logo on the ball will be gone.
To get a bit more life out of a ball, you can "rough it up" on something like an indoor-outdoor carpet You'll have to wash the ball after roughing it up, to get rid of all the tiny rubber particles.
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