The ATP Finals is the second highest tier of men's tennis tournament after the four Grand Slam . The current round robin format of two groups of four players progressing to a semifinal and final, has been in place for all editions of the Prize money : US$7. That will change at London's ATP World Tour Finals next week. At 3pm on Monday, Murray was drawn in the same group as Stan Wawrinka. Official website of the Nitto ATP Finals, the ATP World Tour's season finale November, at The O2 arena in London.