A player stands in the centre of a circle,
holding a tennis ball.
She tries to throw this ball to someone in the circle who will
drop it. Another ball is also being passed around the circle
from one girl to another.
The player in the centre may throw her ball to anyone, but she usually throws it to the girl about to receive the ball being passed around the circle. If either ball is dropped, the one who dropped it changes places with the girl in the centre.