The ATP World Tour Finals is a professional men's tennis tournament held annually in London. It features the top 8 singles players and doubles teams based on rankings over the year. Novak Djokovic is the current singles champion, while Jean-Julen Rojer and Horia Tecau are the current doubles champions. Players can earn prize money up to $2.2 million for an undefeated singles title or $423,000 for an undefeated doubles title.