Right then, I think we'll leave the disappointed words of a broken Murray hanging in the air. Poor man. What a way to end the season.
As for Roger Federer, I'm off to wager a few bob on him winning Wimbledon next year at the age of 33. The supersonic Swiss never ceases to amaze.
Goodnight.
Murray press conference
ReutersCopyright: Reuters
Andy Murray: "It was a tough night. I've lost Slam finals, which has been very tough, but in terms of the way the match went it was not ideal from my side of the court.
"He played exceptionally well. That's for sure. I can say I'm disappointed with my level, but even if I'd played well he probably still would have won. He was striking the ball very cleanly and made very few mistakes. He maybe didn't hit his first serve as well as he can but apart from that everything else was spot on.
"I've never lost 6-0 6-0 before, I've hardly ever lost 6-0 6-1, It's very disappointing, it wasn't what I was looking for.
"He was through in the group, incredibly loose, he was able to try some shots that he might not try in other situations and everything he tried came off."
Post update
Needless to say, Federer finishes top of Group B with Nishikori second. Everything seems to be heading towards a Federer-Djokovic final on BBC television on Sunday night. Reserve your seats.
Get involved
Shohidur Rahman: I was shocked when Murray announced Mauresmo as his coach. It's been a disaster.
Mitch Mansfield: Murrray's been reluctant to use fatigue as an excuse, but fear the schedule that got him to the #ATPWTF could come back to bite.
Demola Oke: Murray winning a game merely prevents this from being a whitewash. It's now just a mere merciless beating.. Federer imperial.
Post update
All this talk of a perfect match from Federer needs a bit of qualifying. In fact, he only got 38% of his first serves in. It didn't matter of course, he won all 14 points when he did get one in and 14 out of 22 points on his second serve. Murray won seven out of 19 points on first, and nine out of 29 on second. I don't think it's a stats sheet that Murray will be pinning to his bedroom wall.
"I'm still optimistic to see Andy Murray challenging for Grand Slams, but he's got a big point to prove to himself in the first three months of next year."
Get involved at #bbctennis
Your reaction on Twitter to an absolute pummelling for Murray:
Alex: "I feel sorry for the people who have paid to watch this. Complete lack of motivation from Murray."
Rob: "Wow, what an exhibition of tennis from Roger Federer. Showing his class here."
Tim: "Federer's time travelling Delorian stuck at 2004. Wow."
Jonathan: "This is an absolute embarrassment. Sporting carnage."
Steve: "I assume this is the end of Mauresmo's tenure as Murray's coach."
How's stat?
Roger Federer won no less than 54 of the 78 points in that match. Astonishing. Murray is trudging back to his dressing room looking utterly distraught. What a humiliating experience for the Olympic champion.
"Everyone who watches a lot of matches knows that is as close to perfection as you can possibly get. Everyone is in shock at that scoreline."
Post update
Roger Federer: "Clearly I'm very happy to play a good match today. I knew I was qualified so maybe I went in a bit more relaxed. It's not the way I thought it was going to go but there's always next year for Andy and hopefully he can have a good season."
Game, set and match Federer
Federer 6-0 6-1 Murray
Murray hangs in there at 30-30 then misses a down the line pass to give Federer match point. The Swiss only needs one to wrap up victory in 56 minutes. Brutal.
Post update
*Federer 6-0 5-1 Murray
From the ridiculous to the sublime as Murray serves his fourth double fault then produces a second serve ace. Game point Murray again. And when Federer can't get his serve back, the O2 crowd respond with one of the biggest cheers of the night.
Time for a comeback worthy of Istanbul or Medinah?
Post update
Federer 6-0 5-0 Murray*
ReutersCopyright: Reuters
Federer proves he's human after all with his first double fault. Murray mutters something unmentionable to himself then dumps another forehand into the net to go 40-15 down. A cushioned volley winner put Federer 5-0 up. The whitewash is almost complete.
Post update
*Federer 6-0 4-0 Murray
Getty ImagesCopyright: Getty Images
Murray puts away an overhead to earn his first game point since the second game of the match. A long rally follows and Murray once again blinks first. Murray sneaks another epic point, but once again wastes his advantage with an unforced error. A forehand into the net and a backhand long take Murray's unforced error count up to 20 and give Federer yet another break.
"It is one of Roger Federer's finest ever performances - absolutely staggering quality of play. At this stage, it must be very difficult for Andy Murray to lift himself. He just wasn't able to live with Federer after about five minutes. Federer won 14 points in a row at one stage."
Post update
Federer 6-0 3-0 Murray*
APCopyright: AP
A glimmer for Murray at 15-30 on the Fed serve but he wastes it by returning a second serve long. Two quick points later and Federer is halfway to winning this second set. When does Murray start thinking about the double bagel? What a horrible humiliation that would be for the British number one.
Post update
*Federer 6-0 2-0 Murray
Murray edges 30-15 ahead but Federer squares up with a perfect drop shot. With the game in the balance, Murray double faults and Federer has another break point. A weak first serve, a blistering return, Murray goes long and it's eight games on the bounce for the Fed Express.
"Federer is having a great time, he looks like his mid-20s when he was in his most dominant dominant years. Federer's movement is incredible and his decision making superb."
Post update
Federer 6-0 1-0 Murray*
Murray's first objective? Win a game. And the signs aren't good as Federer races into a 40-0 lead. Murray's ninth point of the entire match brings a big cheer but another overhit forehand sees another game slip by.
Post update
David Law
BBC Radio 5 live sports extra commentator
"Andy Murray will try his heart out and try to find a way back into the match for his self confidence, his sheer competitive spirit and to give everybody here a show. But what can he do? He's not playing that badly, but is playing the one of the greatest of all time in Roger Federer who has no pressure on him at all."
The Special One's verdict
Jose Mourinho talking to Sky Sports: "There are some matches when we feel it's not our day. That applies to football and any other sport. But he can play for pride and he should play for the people who are behind him. He can only give his best. Sometimes a big defeat is the start of many many victories."
MURRAY IS OUT OF WORLD TOUR FINALS
APCopyright: AP
Sadly folks, that means Murray is out of the tournament, with only pride to play for in the remainder of this match. It's the first time Federer has bageled Murray and his first love set defeat for four years.
Game and first set Federer
*Federer 6-0 Murray
Murray looks shell-shocked as he pushes another forehand beyond the line then nets to open the door to Federer at 30-30. Two weary backhands and the Swiss has the set.
Post update
Federer 5-0 Murray*
Federer is being relentless, serving and volleying to go 40-0 up and forcing Murray into errors with deep, heavy groundstrokes. This is an absolute rout. If Federer wins one more game, Murray is out.
Post update
*Federer 4-0 Murray
Federer unleashes a pearler of a forehand down the line and Murray is starting down the barrel at 0-40. A horrible backhand flies a few yards long and Murray is 4-0 down. If the rot is to be stopped, it has to start now.
Post update
Pantomime boos as the TV cameras pick out Chelsea manager Jose Mourinho in the O2 crowd.
Post update
Federer 3-0 Murray*
ReutersCopyright: Reuters
Federer serves out to love. Murray hardly touches the ball.
Disastrour start for the British number one. Remember, if he loses this set he is out.
"It's the sign of a great champion here with Roger Federer on the break points. He goes after the forehand, doesn't do anything too rash and draws the error."
Post update
*Federer 2-0 Murray
This is already engrossing. Federer plays a masterful point, drawing Murray in then lobbing his with a volley. Murray responds with back-to-back aces but then double faults to leave us at deuce. A backhand into the net gives Murray break point, but Federer squanders it with a wild forehand. But two more Murray errors and Federer is a break up.
Get involved at #bbctennis
You're as divided out there in the world of social media as the O2 crowd. Here's some of your early thoughts...
James: "Murray has to bring the fire tonight, no point going out with a whimper! Head says Roger, heart says Murray! Come on Andy!"
Srikanth: "Just came in after a long day at work! Great way to cap it off. Go Roger!"
John: "Federer to win in two with a second set tie break that's as close as Andy Murray will get to him - he doesn't have enough game for an on fire Federer."
Fissuh: "Matter of justice I wish Andy win but there is no always justice in sports so let the better win. Intense game. Come on Andy."
Post update
Federer 1-0 Murray*
Federer misses a easy put-away then nets a forehand, and Murray has half a chance. Federer fights back to 30-30 then is gifted a point when Murray loops a forehand long. A Murray return catches the tape to put Federer 1-0 up.
"It seems unreal that Federer hasn't got a Grand Slam title this year when you notice he's won 70 matches this season - the highest of any men on tour. He's really put himself out there week in, week out, but hasn't won any of the big ones."
Post update
Service warm-ups underway now. This feels big. Seconds out. Round one.
Post update
At the toss, Federer looks resplendent in a two-tone knitted cardigan, Murray has his standard faded grey T-shirt on. There's a vaguely comical moment as the coin comes to rest against the net, requiring a re-throw. Federer throws his cardie into the crowd and we're into the warm-ups. I can feel the tension and I'm just watching on the goggle-box.
Post update
Getty ImagesCopyright: Getty Images
You gotta love the razzmatazz at the O2. It's kind of showy but stylish at the same time. Murray walks out first to a big cheer, followed by Federer, who almost raises the roof.
VOTE: Will Andy Murray beat Roger Federer?
The vote is now closed - thank you for participating.
A significant 66.4% of you DON'T think Murray can beat Federer tonight.
With just 33.6% of you believing Murray can win, Rory tweets the evening's rallying cry: "Come on Andy!!!"
Pre-match patter
Andy Murray: "It's going to be a tough match, a great atmosphere, packed house. I'm looking forward to it. I need to play well, that's very important. I will have to be intense, not give away any game, reduce unforced errors and be aggressive."
Roger Federer: "Andy needs and wants to win this match. I'm aware of that challenge. I have to play my game be aggressive and stick to what's been working these last few weeks and months."
Post update
Federer, meanwhile, has been talking up his opponent's chances, saying Murray's confidence will be boosted by his recent upsurge in form.
"I'm sure his belief is higher now again," said six-time champion Federer. "Beating David Ferrer twice, and Marin Cilic as well in Beijing, Jo-Wilfried Tsonga at the US Open - those are the matches he needed to win down the stretch at the end of the season, which he did."
Post update
Murray says he's fully prepared to hear members of his supposed home crowd cheering for Federer. "The crowd will probably be more split when I play against Roger but that's no surprise," he wrote in his BBC Sport column.
"I've played him all over the world - in Asia, America, Australia, Canada and Europe, at Wimbledon and three times at the O2 - and pretty much everywhere he goes he gets very good support."
Get involved
Stewart Mills: Going to be an intense battle tonight. Both Murray and the Federer will be desperate to avoid Djokovic in the semis.
Post update
Piers Newbery
BBC Sport at the O2 Arena in London
Getty ImagesCopyright: Getty Images
"After 24 hours of poor maths, double-checking and questions that begin with "so does it come down to sets won or games percentage….?", it's all very simple. And I am yet to find anyone who thinks Murray will beat Federer in straight sets. That makes sense based on recent history but probably underplays the fact that they have an 11-11 head-to-head record, and there is something on the line for Federer tonight as a defeat would probably leave him facing Djokovic in the semi-finals. An unenviable task at the moment."
Post update
Andy Murray last beat the Swiss superstar in straight sets in the Shanghai Masters semi-final in October 2012 - 6-4 6-4.
For those of you, like me, who might have been preparing to scour the archives for the last time the ever popular Roger Federer lost in straight sets - to anyone - fear not.
It happened as recently as the Paris Masters quarter-final when Milos Raonic won 7-6 (7-5) 7-5. This is what it looks like.
Getty ImagesCopyright: Getty Images
Needle
BBC Radio 5 live sports extra pundits have been having their say on the Federer-Murray rivalry.
Colin Fleming, Andy Murray's Great Britain Davis Cup doubles partner, says: "We hear them both say it is a pleasure to play each other, but they get under each other's skin on court and really want to beat each other. I'm expecting a real fierce encounter."
Miles Maclagan, Andy Murray's former coach, says: "I think a lot of that came from the time before Murray had won his Grand Slams and in the media we talked about 'the big four'. Federer probably felt 'why are you putting him in our class?' Until recently, Andy had a winning head-to-head record against Federer, which he wouldn't have liked."
Commentator David Law offers: "There was that moment when Andy Murray got to the final of the 2010 Australian Open and Federer made a comment along the lines of 'It's a big day for Andy, they haven't won a Grand Slam in about 150,000 years'. And there have been a few other barbs along the way."
Play nice boys
Getty ImagesCopyright: Getty Images
While Murray and Federer themselves talk of "great respect" and offer little hint of any animosity, those in and around the dressing rooms on tour suggest there's a fair bit of niggle between the two.
We'll be watching carefully for body shots, trash talk and a lack of tennis etiquette if this one turns ugly.
Keeping up?
Murray's chances have not been helped by Kei Nishikori's three-set victory over David Ferrer earlier today. The Spaniard was a late replacement for Canada's Milos Raonic, who pulled out at lunchtime with a quad injury. Here's how Group B is panning out following that result.
BBCCopyright: BBC
VOTE: Will Andy Murray beat Roger Federer?
There's nothing like an important Andy Murray tennis match to divide public opinion.
We'll be running a vote until just before tonight's encounter begins and we want you to have your say on whether Murray will beat the 17-time Grand Slam champion.
Just head to the right of the screen and cast your vote - or tweet to @BBCSport 'yes' or 'no'.
Head to Head
What a rivalry this has been over the years. In 22 meetings, they are tied at 11 wins apiece. Murray leads 6-2 in their Masters matches but Federer has a 4-1 lead in Slams and has won both their meetings this year. The Swiss has also won all three of their previous meetings at the O2, where both players are expected to receive huge support.
BBCCopyright: BBC
Post update
I say within reach. In truth, it's a tall order facing Murray against the 17-time Grand Slam champion, who is already through to the last four. In order to join the Swiss in the semi-finals, Murray must not only win, but win in straight sets.
Post update
ReutersCopyright: Reuters
It's been a tough old year for Andy Murray. Struggling to overcome the effects of back surgery, losing his Wimbledon crown, dropping outside the world's top 10 for the first time since 2008 and getting himself into a political pickle over Scottish independence.
And yet, following a recent upturn in form, there is still hope of a glorious ending to 2014 for the British number one.
Tonight he takes on his great rival Roger Federer at the O2 Arena in London with a place in the semi-finals of the World Tour Finals still within his reach.
Live Reporting
By Sam Sheringham
All times stated are UK
Get involved
Post update
Right then, I think we'll leave the disappointed words of a broken Murray hanging in the air. Poor man. What a way to end the season.
As for Roger Federer, I'm off to wager a few bob on him winning Wimbledon next year at the age of 33. The supersonic Swiss never ceases to amaze.
Goodnight.
Murray press conference
Andy Murray: "It was a tough night. I've lost Slam finals, which has been very tough, but in terms of the way the match went it was not ideal from my side of the court.
"He played exceptionally well. That's for sure. I can say I'm disappointed with my level, but even if I'd played well he probably still would have won. He was striking the ball very cleanly and made very few mistakes. He maybe didn't hit his first serve as well as he can but apart from that everything else was spot on.
"I've never lost 6-0 6-0 before, I've hardly ever lost 6-0 6-1, It's very disappointing, it wasn't what I was looking for.
"He was through in the group, incredibly loose, he was able to try some shots that he might not try in other situations and everything he tried came off."
Post update
Needless to say, Federer finishes top of Group B with Nishikori second. Everything seems to be heading towards a Federer-Djokovic final on BBC television on Sunday night. Reserve your seats.
Get involved
Shohidur Rahman: I was shocked when Murray announced Mauresmo as his coach. It's been a disaster.
Mitch Mansfield: Murrray's been reluctant to use fatigue as an excuse, but fear the schedule that got him to the #ATPWTF could come back to bite.
Demola Oke: Murray winning a game merely prevents this from being a whitewash. It's now just a mere merciless beating.. Federer imperial.
Post update
All this talk of a perfect match from Federer needs a bit of qualifying. In fact, he only got 38% of his first serves in. It didn't matter of course, he won all 14 points when he did get one in and 14 out of 22 points on his second serve. Murray won seven out of 19 points on first, and nine out of 29 on second. I don't think it's a stats sheet that Murray will be pinning to his bedroom wall.
Post update
Russell Fuller
BBC tennis correspondent on Radio 5 live sports extra
"I'm still optimistic to see Andy Murray challenging for Grand Slams, but he's got a big point to prove to himself in the first three months of next year."
Get involved at #bbctennis
Your reaction on Twitter to an absolute pummelling for Murray:
Alex: "I feel sorry for the people who have paid to watch this. Complete lack of motivation from Murray."
Rob: "Wow, what an exhibition of tennis from Roger Federer. Showing his class here."
Tim: "Federer's time travelling Delorian stuck at 2004. Wow."
Jonathan: "This is an absolute embarrassment. Sporting carnage."
Steve: "I assume this is the end of Mauresmo's tenure as Murray's coach."
How's stat?
Roger Federer won no less than 54 of the 78 points in that match. Astonishing. Murray is trudging back to his dressing room looking utterly distraught. What a humiliating experience for the Olympic champion.
Post update
Jeremy Bates
Former British number one on BBC Radio 5 live sports extra
"Everyone who watches a lot of matches knows that is as close to perfection as you can possibly get. Everyone is in shock at that scoreline."
Post update
Roger Federer: "Clearly I'm very happy to play a good match today. I knew I was qualified so maybe I went in a bit more relaxed. It's not the way I thought it was going to go but there's always next year for Andy and hopefully he can have a good season."
Game, set and match Federer
Federer 6-0 6-1 Murray
Murray hangs in there at 30-30 then misses a down the line pass to give Federer match point. The Swiss only needs one to wrap up victory in 56 minutes. Brutal.
Post update
*Federer 6-0 5-1 Murray
From the ridiculous to the sublime as Murray serves his fourth double fault then produces a second serve ace. Game point Murray again. And when Federer can't get his serve back, the O2 crowd respond with one of the biggest cheers of the night.
Time for a comeback worthy of Istanbul or Medinah?
Post update
Federer 6-0 5-0 Murray*
Federer proves he's human after all with his first double fault. Murray mutters something unmentionable to himself then dumps another forehand into the net to go 40-15 down. A cushioned volley winner put Federer 5-0 up. The whitewash is almost complete.
Post update
*Federer 6-0 4-0 Murray
Murray puts away an overhead to earn his first game point since the second game of the match. A long rally follows and Murray once again blinks first. Murray sneaks another epic point, but once again wastes his advantage with an unforced error. A forehand into the net and a backhand long take Murray's unforced error count up to 20 and give Federer yet another break.
Post update
Russell Fuller
BBC tennis correspondent on Radio 5 live sports extra
"It is one of Roger Federer's finest ever performances - absolutely staggering quality of play. At this stage, it must be very difficult for Andy Murray to lift himself. He just wasn't able to live with Federer after about five minutes. Federer won 14 points in a row at one stage."
Post update
Federer 6-0 3-0 Murray*
A glimmer for Murray at 15-30 on the Fed serve but he wastes it by returning a second serve long. Two quick points later and Federer is halfway to winning this second set. When does Murray start thinking about the double bagel? What a horrible humiliation that would be for the British number one.
Post update
*Federer 6-0 2-0 Murray
Murray edges 30-15 ahead but Federer squares up with a perfect drop shot. With the game in the balance, Murray double faults and Federer has another break point. A weak first serve, a blistering return, Murray goes long and it's eight games on the bounce for the Fed Express.
Post update
Jeremy Bates
Former British number one on BBC Radio 5 live sports extra
"Federer is having a great time, he looks like his mid-20s when he was in his most dominant dominant years. Federer's movement is incredible and his decision making superb."
Post update
Federer 6-0 1-0 Murray*
Murray's first objective? Win a game. And the signs aren't good as Federer races into a 40-0 lead. Murray's ninth point of the entire match brings a big cheer but another overhit forehand sees another game slip by.
Post update
David Law
BBC Radio 5 live sports extra commentator
"Andy Murray will try his heart out and try to find a way back into the match for his self confidence, his sheer competitive spirit and to give everybody here a show. But what can he do? He's not playing that badly, but is playing the one of the greatest of all time in Roger Federer who has no pressure on him at all."
The Special One's verdict
Jose Mourinho talking to Sky Sports: "There are some matches when we feel it's not our day. That applies to football and any other sport. But he can play for pride and he should play for the people who are behind him. He can only give his best. Sometimes a big defeat is the start of many many victories."
MURRAY IS OUT OF WORLD TOUR FINALS
Sadly folks, that means Murray is out of the tournament, with only pride to play for in the remainder of this match. It's the first time Federer has bageled Murray and his first love set defeat for four years.
Game and first set Federer
*Federer 6-0 Murray
Murray looks shell-shocked as he pushes another forehand beyond the line then nets to open the door to Federer at 30-30. Two weary backhands and the Swiss has the set.
Post update
Federer 5-0 Murray*
Federer is being relentless, serving and volleying to go 40-0 up and forcing Murray into errors with deep, heavy groundstrokes. This is an absolute rout. If Federer wins one more game, Murray is out.
Post update
*Federer 4-0 Murray
Federer unleashes a pearler of a forehand down the line and Murray is starting down the barrel at 0-40. A horrible backhand flies a few yards long and Murray is 4-0 down. If the rot is to be stopped, it has to start now.
Post update
Pantomime boos as the TV cameras pick out Chelsea manager Jose Mourinho in the O2 crowd.
Post update
Federer 3-0 Murray*
Federer serves out to love. Murray hardly touches the ball.
Disastrour start for the British number one. Remember, if he loses this set he is out.
Post update
Jeremy Bates
Former British number one on BBC Radio 5 live sports extra
"It's the sign of a great champion here with Roger Federer on the break points. He goes after the forehand, doesn't do anything too rash and draws the error."
Post update
*Federer 2-0 Murray
This is already engrossing. Federer plays a masterful point, drawing Murray in then lobbing his with a volley. Murray responds with back-to-back aces but then double faults to leave us at deuce. A backhand into the net gives Murray break point, but Federer squanders it with a wild forehand. But two more Murray errors and Federer is a break up.
Get involved at #bbctennis
You're as divided out there in the world of social media as the O2 crowd. Here's some of your early thoughts...
James: "Murray has to bring the fire tonight, no point going out with a whimper! Head says Roger, heart says Murray! Come on Andy!"
Srikanth: "Just came in after a long day at work! Great way to cap it off. Go Roger!"
John: "Federer to win in two with a second set tie break that's as close as Andy Murray will get to him - he doesn't have enough game for an on fire Federer."
Fissuh: "Matter of justice I wish Andy win but there is no always justice in sports so let the better win. Intense game. Come on Andy."
Post update
Federer 1-0 Murray*
Federer misses a easy put-away then nets a forehand, and Murray has half a chance. Federer fights back to 30-30 then is gifted a point when Murray loops a forehand long. A Murray return catches the tape to put Federer 1-0 up.
Post update
Jeremy Bates
Former British number one on BBC Radio 5 live sports extra
"It seems unreal that Federer hasn't got a Grand Slam title this year when you notice he's won 70 matches this season - the highest of any men on tour. He's really put himself out there week in, week out, but hasn't won any of the big ones."
Post update
Service warm-ups underway now. This feels big. Seconds out. Round one.
Post update
At the toss, Federer looks resplendent in a two-tone knitted cardigan, Murray has his standard faded grey T-shirt on. There's a vaguely comical moment as the coin comes to rest against the net, requiring a re-throw. Federer throws his cardie into the crowd and we're into the warm-ups. I can feel the tension and I'm just watching on the goggle-box.
Post update
You gotta love the razzmatazz at the O2. It's kind of showy but stylish at the same time. Murray walks out first to a big cheer, followed by Federer, who almost raises the roof.
VOTE: Will Andy Murray beat Roger Federer?
The vote is now closed - thank you for participating.
A significant 66.4% of you DON'T think Murray can beat Federer tonight.
With just 33.6% of you believing Murray can win, Rory tweets the evening's rallying cry: "Come on Andy!!!"
Pre-match patter
Andy Murray: "It's going to be a tough match, a great atmosphere, packed house. I'm looking forward to it. I need to play well, that's very important. I will have to be intense, not give away any game, reduce unforced errors and be aggressive."
Roger Federer: "Andy needs and wants to win this match. I'm aware of that challenge. I have to play my game be aggressive and stick to what's been working these last few weeks and months."
Post update
Federer, meanwhile, has been talking up his opponent's chances, saying Murray's confidence will be boosted by his recent upsurge in form.
"I'm sure his belief is higher now again," said six-time champion Federer. "Beating David Ferrer twice, and Marin Cilic as well in Beijing, Jo-Wilfried Tsonga at the US Open - those are the matches he needed to win down the stretch at the end of the season, which he did."
Post update
Murray says he's fully prepared to hear members of his supposed home crowd cheering for Federer. "The crowd will probably be more split when I play against Roger but that's no surprise," he wrote in his BBC Sport column.
"I've played him all over the world - in Asia, America, Australia, Canada and Europe, at Wimbledon and three times at the O2 - and pretty much everywhere he goes he gets very good support."
Get involved
Stewart Mills: Going to be an intense battle tonight. Both Murray and the Federer will be desperate to avoid Djokovic in the semis.
Post update
Piers Newbery
BBC Sport at the O2 Arena in London
"After 24 hours of poor maths, double-checking and questions that begin with "so does it come down to sets won or games percentage….?", it's all very simple. And I am yet to find anyone who thinks Murray will beat Federer in straight sets. That makes sense based on recent history but probably underplays the fact that they have an 11-11 head-to-head record, and there is something on the line for Federer tonight as a defeat would probably leave him facing Djokovic in the semi-finals. An unenviable task at the moment."
Post update
Andy Murray last beat the Swiss superstar in straight sets in the Shanghai Masters semi-final in October 2012 - 6-4 6-4.
For those of you, like me, who might have been preparing to scour the archives for the last time the ever popular Roger Federer lost in straight sets - to anyone - fear not.
It happened as recently as the Paris Masters quarter-final when Milos Raonic won 7-6 (7-5) 7-5. This is what it looks like.
Needle
BBC Radio 5 live sports extra pundits have been having their say on the Federer-Murray rivalry.
Colin Fleming, Andy Murray's Great Britain Davis Cup doubles partner, says: "We hear them both say it is a pleasure to play each other, but they get under each other's skin on court and really want to beat each other. I'm expecting a real fierce encounter."
Miles Maclagan, Andy Murray's former coach, says: "I think a lot of that came from the time before Murray had won his Grand Slams and in the media we talked about 'the big four'. Federer probably felt 'why are you putting him in our class?' Until recently, Andy had a winning head-to-head record against Federer, which he wouldn't have liked."
Commentator David Law offers: "There was that moment when Andy Murray got to the final of the 2010 Australian Open and Federer made a comment along the lines of 'It's a big day for Andy, they haven't won a Grand Slam in about 150,000 years'. And there have been a few other barbs along the way."
Play nice boys
While Murray and Federer themselves talk of "great respect" and offer little hint of any animosity, those in and around the dressing rooms on tour suggest there's a fair bit of niggle between the two.
We'll be watching carefully for body shots, trash talk and a lack of tennis etiquette if this one turns ugly.
Keeping up?
Murray's chances have not been helped by Kei Nishikori's three-set victory over David Ferrer earlier today. The Spaniard was a late replacement for Canada's Milos Raonic, who pulled out at lunchtime with a quad injury. Here's how Group B is panning out following that result.
VOTE: Will Andy Murray beat Roger Federer?
There's nothing like an important Andy Murray tennis match to divide public opinion.
We'll be running a vote until just before tonight's encounter begins and we want you to have your say on whether Murray will beat the 17-time Grand Slam champion.
Just head to the right of the screen and cast your vote - or tweet to @BBCSport 'yes' or 'no'.
Head to Head
What a rivalry this has been over the years. In 22 meetings, they are tied at 11 wins apiece. Murray leads 6-2 in their Masters matches but Federer has a 4-1 lead in Slams and has won both their meetings this year. The Swiss has also won all three of their previous meetings at the O2, where both players are expected to receive huge support.
Post update
I say within reach. In truth, it's a tall order facing Murray against the 17-time Grand Slam champion, who is already through to the last four. In order to join the Swiss in the semi-finals, Murray must not only win, but win in straight sets.
Post update
It's been a tough old year for Andy Murray. Struggling to overcome the effects of back surgery, losing his Wimbledon crown, dropping outside the world's top 10 for the first time since 2008 and getting himself into a political pickle over Scottish independence.
And yet, following a recent upturn in form, there is still hope of a glorious ending to 2014 for the British number one.
Tonight he takes on his great rival Roger Federer at the O2 Arena in London with a place in the semi-finals of the World Tour Finals still within his reach.