The Nitto ATP Finals is the year-end climax to the men's professional tennis season, featuring only the world's best eight qualified singles players and doubles teams as they battle it out for the last title of the season. Players compete for ATP Rankings points throughout the season in a bid to earn one of the eight coveted berths. Played using a round-robin format at The O2 in London, each participant plays three matches as they compete for a berth in the knockout semi-finals and beyond. An undefeated champion earns 1,500 ATP Rankings points. Total prize money offered is USD 8.5 million.