Complex sentence: The first time the ball is stopped a "ratlla" (line) is marked on the ground, if the second time the ball is stopped it has been thrown over that "ratlla" the point is won by the sender.
Split into simpler sentences: The first time the ball is stopped a "ratlla" (line) is marked on the ground. The second time the ball is stopped it has been thrown over that "ratlla," the point is won by the sender.