soon to be gone from the wikipedia tetherball page
"An alternate version of the game and sold as Swingball uses a smaller, softer ball that the players strike with racquets. It can be described as "tether tennis", and is more popular in the United Kingdom. Swingball has a shorter pole, is portable and the ball flies around the pole at a constant distance from the pole on a helical screw; the game ends when the ball reaches the top or bottom of the screw. Generally the ball used for these games is an old tennis ball, and the racquets can come from ping-pong or games with similar paddles.