I found this game on the Tennis Resources site. They had it in a doubles format, but I can see
Teams start out with nine points each. Coach feeds in the first ball. Players play out the point. Losing team loses a 'life'. Play continues until one team is out of lives. Play best two out of three, with coach feeding a different team each round.
How about this singles variation, especially if you have odd numbers or a larger group: One player is on one end alone; all others are at the other end. One by one, they take on the singleton. All players begin with 9 Lives, losing one each time they lose a point. Player with the most lives when someone gets down to zero is the new singleton.