Claim: Novak Djokovic is a professional tennis player and is successful.
Evidence: Novak Djokovic -LRB- Новак Ђоковић , Novak Đoković , -LSB- nôʋaːk d͡ʑôːkoʋit͡ɕ -RSB- ; born 22 May 1987 -RRB- , 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 -LRB- ATP -RRB-.