London: Novak Djokovic will look to set the seal on a "great year" at the ATP World Tour Finals in London.
The Serb begins his quest to win the season-ending tournament featuring most of the world's top players when he faces Jo-Wilfried Tsonga on Monday, the same day Djokovic is restored to the number one world ranking, having finished last year on top of the standings as well.
"It's been a great year again," Djokovic, who won the first Grand Slam of 2012 when he triumphed at the Australian Open, told Sky Sports on Sunday.
"After 2011 it has been the best year of my career. Not just for me but for many players -- we have four different grand slam winners and I think the season finale could not come at a better time."
Djokovic appears to be in the tougher of the two first round groups with Britain's Andy Murray, who beat him in a gruelling US Open final, and the big-serving Tomas Berdych as well as Tsonga amongst his opponents.
By contrast defending champion Roger Federer is in a Group B featuring former US Open champion Juan Martin del Potro, David Ferrer and Janko Tipsarevic with the Swiss's long-time foe Rafael Nadal missing as he continues his recovery from a knee injury.
However, Ferrer won the Paris Masters on Sunday and Federer, speaking before the Spaniard's triumph in France, warned of the clay-court expert's quality on the kind of indoor surface that will greet the players at London's O2 Arena.
"Obviously the big (question) was whether Murray was going to be in my group or not I guess," said Federer, who beat the British star in the Wimbledon final before losing to the Scot in the Olympic gold medal match on Centre Court just a few weeks later.
"Now that Nadal is not here you feel that maybe Ferrer is not Nadal, so it's better to have Ferrer in the draw.
"But then again Ferrer has had his major upsets at the World Tour Finals. I played him once in the finals and once in the semis and they were indoors.
"Normally we think Ferrer is not the best indoor player -- but he has just won Valencia and he might win Paris so it's overall a tough group for both of us and all players and it's exciting.
"That is why we come here and play and that is why the fans come out to watch," Federer added.