Novak Djokovic (Serbian: Новак Ђоковић, Novak Đoković, pronounced ( listen); born 22 May 1987), often referred to by the hypocorism Nole, is a Serbian professional tennis player who is currently ranked world No. 2 in men's singles tennis by the Association of Tennis Professionals (ATP). He is considered one of the greatest tennis players of all time. He is coached by former Slovak tennis player Marián Vajda. Djokovic holds the best match winning rate (83.00%) in Open Era, as of August 2016.