In of tetherball, one player serves, then either player can hit the ball from that point on. Under these rules, the server has an immense advantage. She has complete control of the ball from the start of the game, and if she's an advanced player facing an opponent of equal skill, she should be able to hit the ball over her opponent each time it comes around, wrapping it to win the game without her opponent even touching the ball.
requires the server to wait until either the opponent strikes the ball or the ball has wrapped four times before she can strike the ball again. This actually gives the receiver the advantage, because he gets the first chance at unrestricted control of the ball. His advantage, though, is tempered by the fact that the server can wind the ball at least one wrap in her own direction and use an angled serve to prevent him from getting a clean first hit on the ball. This makes the contest as fair as it can be, although winning one's serving games is still about as rare in advanced tetherball as breaking serve is in advanced tennis.