Andy Murray is seeded third in London
In the absence of the injured Rafael Nadal, the battle for the ATP World Tour Finals is shaping up to be a three-horse race.
Novak Djokovic will end the year as world No. 1 and the Serb is the bookies' favourite with odds of 2/1 with bet365.
But home advantage could prove to be the difference for US Open champion Andy Murray (9/4), who has clearly enjoyed playing on home soil this season after reaching the Wimbledon final and winning Olympic gold at London 2012.
Roger Federer is hunting a record seventh year-end title, but his recent form is reflected in his odds of 11/4.
For those looking for more value, Juan Martin Del Potro, who defeated Federer in the Swiss Indoors final recently, is a tempting 9/1 with bet365.