Edited sentence: Djokovic insists this is not so and that he does it to calm himself down.He has been known to bounce the ball up to twenty times.He says that he is aware of the problem and is working on it.His controversial excessive ball-bouncing before serve has been talked about a great deal.It is thought that he deliberately does this to irritate or put off opponents.The problem however persists up to the current French open where he has been repeatedly jeered by members of the crowd or teased by his opponents