Djokovic not 'obliged' to win

Novak Djokovic is adamant his 2011 season will not be ruined if he fails to win the ATP World Tour finals.The tournament, which starts on Sunday at London's O2 Arena and will be shown live on Sky Sports, features the top eight players in the world rankings, fighting it out in a round-robin format.Divided into two groups, the World No.1 is up against Andy Murray, Czech Tomas Berdych and Spain's David Ferrer in his round-robin matches.When he comes up against Murray, Djokovic will face one of the few players who has beaten him this season as the Serb heads to London with a 69-4 record for 2011.But he insists, if he doesn't win the Finals, it will not detract from what has been a phenomenal season."I don't feel obliged to win the tournament in order to make this season perfect but I will do my best to prepare and finish off the season in style," he said.Former world No1 Boris Becker reckons Djokovic's 2011 season has been one of the "best years in tennis of all time".Heading into the ATP World Tour Finals, Djokovic is secure in the number one ranking with 13,475 points, 4,100 ahead of second-placed Rafael Nadal.His points have come largely through his three Grand Slam titles with the Serb only missing out on the French Open where he was beaten by Roger Federer in the semi-finals.Added to those three titles, he has also won another seven, having started the season with an impressive run of 41 matches undefeated.With just four defeats compared to 69 match wins, Djokovic is on a season-best 94.5 percent. However, that's not the best as in 2006 Federer had a record of 94.9 percent."I would consider that to be one of the very best years in tennis of all time," Becker told Bloomberg."He's won three Grand Slams, he's beaten the No.1 player at the time in six consecutive finals. That has never happened."It may not be the best statistically, but he's beaten Federer, he's beaten Nadal, he's beaten everybody that came around to challenge him in the biggest tournaments in the world."That's why I think it was just an unbelievable year."