As far as Helen could tell, there were 10 balls in play. Each team had 10 members for a total of 20 players on the field, but there were only 10 silver balls. Every player was trying to take a ball and run it down field to their own side.
Something in the gloves the players wore allowed those without a ball to steal balls from players that had them. But to do this, they had to be positioned exactly beside the player with the ball. Then they could click the ball to their own hands without touching the other player. However, if positioned correctly, the person from whom the ball had been stolen could click back the ball.
Silver balls were in play all over the field.