Andy Murray's rise to the top of the rankings this fall has been a surprising tale containing numerous improbable elements. So it's hardly shocking to discover that in his own eyes, not playing has had as much to do with Murray's spectacular results as his exploits on the court.

"I've managed my rest and recovery periods much better," Murray told ESPN's Darren Cahill on Friday, following Murray's tidy, 6-4, 6-2 win against Stan Wawrinka in the final round of round-robin play in the ATP World Tour Finals. "In the past, after a tournament or a loss, I would get right back out there on the court to play, or to practice."

It's different now. After Murray won the Paris Masters 1000, he explained he resisted the impulse to pick up a racket for four days during the week before the World Tour Finals. He also laid aside his sticks for a week after he won the Shanghai Masters. It could not have been an easy decision for Murray to take, because he owes a great deal of his success to his work ethic.

Andy Murray will take a 22-match winning streak into Saturday's World Tour Finals battle against Milos Raonic. Reuters / Toby Melville

Murray has a well-earned reputation as a workaholic. If you've known anyone like that, you know how much comfort they take in the sheer act of working. How secure it makes them feel. But what if the work isn't paying off, or it's become just a hedge against feeling inadequate?

Changing his work habits could not have been an easy decision for Murray to make. But he took the plunge. The successful result is further proof of Murray's reputation as a man who has left no stone unturned in his quest for greatness. In having the confidence and poise to try that somewhat counter-intuitive change, the 29-year-old Scot set himself up to equal the best winning streak of his career (22 matches) with this win over Wawrinka. More importantly, Murray positioned himself for a showdown with Novak Djokovic this weekend for the year-end No. 1 ranking.

"I feel good," Murray said, despite a season workload that has produced a 76-9 singles record and eight titles. "Obviously, I've played a lot, but my body is just conditioned to matches."

Murray's mind is similarly steeled to the task at hand. It can be dispiriting to be frowned upon by the gods of the draw while a rival seems to get a path to a semi or final as slick as a luge run. This week, the seemingly smooth ride was offered to Djokovic, whose cumulative record against the three other men in his round-robin portion was a perfect 23-0.

That might have been especially discouraging for Murray, because of his already mediocre record at the O2 Arena coming in. Despite having nine previous chances to crack the World Tour Finals code, he was just 11-11 -- and never a finalist. His own draw this year was brutal: Murray was 27-12 against Marin Cilic, Kei Nishikori and Wawrinka.

But Murray did more than survive; he flourished. He made a powerful statement in locking down the three W's in round-robin play this year, because he's also been forced to march in lockstep with Djokovic all the way. Whoever does better in this tournament will take that grand prize, the top ranking.

Murray's win against Wawrinka was deft, swift and critical. He accomplished it in 1 hour, 25 minutes, avoiding the kind of knockdown, drag-out battle he survived with Nishikori in the second round. It means Murray, who unlike Djokovic will not get a day off before the semifinals, ought to recover more easily and have sufficient spring in his legs.

Murray is entitled to feel like he's gotten over the hump, even though his job is far from finished. He seems to have come to grips with the pressure he faces from his fellow British countrymen annually at the O2 arena. He also has a right to feel he's got the upper hand on his three potential rivals, starting with Saturday's semifinal opponent, Milos Raonic.

If Murray's success makes Djokovic slightly uneasy or makes him wish he were better prepared for the semifinals, it's an earned bonus.

Murray was a juggernaut entering this event, and he remains one just two matches from its conclusion. On Friday, Murray broke a string during the first point of the final game. He played on, hitting three slice backhands, a lob and a slice approach before Wawrinka ended the point with a passing-shot winner. It's almost unheard of for a player to construct such a point through so many shots with a racket that's essentially unraveling in his hand.

But that's the kind of year Murray has had, and it's difficult not to read the incident as an omen.