Andy Murray does not feel any different having become the new world number one, and is anticipating a renewed challenge from Novak Djokovic.
Murray was confirmed as number one last Saturday when Milos Raonic pulled out of their semi-final at the Paris Masters, with that walkover win following Djokovic's loss in the quarters to Marin Cilic.
The Briton will now attempt to win the ATP World Tour Finals for the first time and, speaking at a media conference, he said: "I would consider it the best year I've had on court, the last few months have obviously been the best in terms of my consistency.
"Even the matches I've lost were really close matches, ones I potentially could have won.
"I don't feel any different this week than I did the week before, maybe when you step on the court you have a little more confidence. I didn't feel much different when I woke up on Monday morning, I feel just the same."
Despite overhauling Djokovic in the rankings following the Serbian's recent dip in form, Murray insists talk of the 12-time grand slam champion's demise is premature.
"I expect Novak is going to start playing his best tennis again, last couple of months he hasn't, but before then he'd been playing great," he added.
"It wasn't months it was years he was playing great tennis for. For him not to play his best for a couple of months, I'm sure for him is not too much to worry about. I imagine shortly he'll be back to playing his best. There's no reason to think he won't have a really good tournament here."
Murray has been drawn in the John McEnroe Group in the season-ending showpiece and will take on US Open champion Stan Wawrinka, as well as Kei Nishikori - who beat him at Flushing Meadows - and Cilic.
On the surface at the O2 Arena, he said: "The court is definitely a bit faster this year, that changes the way you play but I think that's a positive thing.
"At the end of the year when the players have played a lot of tennis, to have it on the slowest court - really, really long rallies is tough. It will maybe make for some better tennis."