(For) the use of one ball at $29.97 from Accel Digital Solutions, you would have to have 10-20 or so of the traditional balls that you would go through," he said. You can visit the company's ...

The rules of tennis say that the ball must bounce between 53 and 58 inches after being dropped on to concrete from a height of 100 inches. That is why balls are changed during tournaments - they begin ...