Monday 23 November 2015 13:40, UK
After the ATP World Tour Finals brought the season to a thrilling close, we pick out five talking points from the elite eight-man tournament.
Novak Djokovic added a final title to his 2015 collection, but what else did we learn in London last week?
With Britain's Davis Cup final edging closer, there had been suggestions that Murray would not push his body to the limit in London.
But the Scot's commitment could not have been questioned as he desperately battled against elimination in his last group game against Stan Wawrinka.
Murray could have been forgiven for turning his thoughts to the final in Ghent when he dropped the opening set and was broken twice in the second set.
But the world No 2 mounted a thrilling late fightback in front of his home fans, hauling back a break and narrowly missing out on another as Wawrinka eventually served out for a place in the semi-finals.
Murray may well have failed to qualify from his group, but it was not through a lack of effort.
Murray did not add to two Grand Slam titles this year, but his consistency throughout the season has seen him finish a career-high second in the world rankings, behind the men's dominant ruler Novak Djokovic.
Considering the Serb's masterful form throughout the past 12 months, it's no surprise that he has amassed almost 8,000 more points than his nearest rival Murray.
But the Scot's position at the head of the chasing pack is testament to his impressive form on all surfaces, with ATP Tour title wins on clay, hard courts and the grass, leaving him ahead of Roger Federer, Stan Wawrinka and Rafael Nadal.
Whether the Brit can threaten Djokovic's top spot in 2016 remains to be seen, but he has continued to make promising strides.
The world No 1 ended the year as he had started it, lifting a title in front of an awe-struck crowd.
Djokovic has stood head and shoulders above his rivals for most of the season, winning three of the four Grand Slam titles on offer, with only the French Open crown escaping his grasp following a surprise defeat to Wawrinka in the final.
Federer threatened to spoil Djokovic's closing party by inflicting a straight sets defeat in the group stages of the ATP World Tour Finals.
But Djokovic set the record straight in the final, completing a ruthless 6-3 6-4 win of his own to administer one last rap on the knuckles to his long-term foe.
It would seem that only injury can disrupt the dominance of Djokovic, who at the age of 28 can surely look forward to many more final appearances.
With 17 Grand Slam titles to his name, Federer should have approached another final appearance with ice-cool composure.
But Sky Sports expert Annabel Croft believes she saw cracks in Federer's focus as he faced-off against Djokovic, who had previously defeated him in this year's Wimbledon and US Open finals.
Federer was unable to breach his opponent's famed defence throughout, failing to claim a single break of serve as he slumped to defeat.
You sensed tension and nerves on the bigger points and I think that's why Novak has won the bigger titles against him in their previous match-ups.
Speaking afterwards, Croft told Sky Sports: "Sitting down at court-side you could sense the tension running through [Federer's] body. Every time he got a little sniff of an opportunity to get himself back in the match - I never felt like he played with complete and utter freedom.
"You sensed tension and nerves on the bigger points and I think that's why Novak has won the bigger titles against him in their previous match-ups. The two Wimbledon titles and the US Open, those are the bigger events, and he could sense that pressure that had been built up."
Nadal can take more positives from his performances in London, which included a comfortable 6-4 6-1 win over Andy Murray.
The Spaniard overcame an early break and wore down the Scot's resolve with an array of ferocious ground strokes, sealing victory with a swagger.
Nadal, who ended the group stages with three wins, could not extend his promising run against Djokovic as he departed the tournament with a straight sets defeat.
But after a difficult year, which saw Nadal finally lose his French Open title, the 29-year-old will be heartened by a string of promising results in the last few months.
Nadal, a losing finalist in Basel and Shanghai, was beginning to show some promising signs of a recovery when the season came to a halt.
