|US Open, Flushing Meadows, New York|
|Dates: 25 August-8 September Coverage: Live radio and text commentary on Andy Murray's matches and all quarter-finals onwards, plus commentary every day from 18:00 or 18:30 BST on BBC Radio 5 live sports extra|
Andy Murray needs to find his best serving form, sharpen up from the baseline and stay rock solid mentally if he is to beat Novak Djokovic at the US Open.
Those are the views of the analyst and the ex-player as Murray prepares to face a daunting, if familiar, challenge in the US Open quarter-finals.
"Andy needs to go in there prepared to be as mentally and physically strong as possible," said Tim Henman, a US Open semi-finalist in 2004.
"You're not going to get any gifts. They play similar styles. It's about who can be aggressive, take their chances and limit their unforced errors.
"You can't just go for everything against a guy like Djokovic and make loads of mistakes. You have to get the balance right."
|BBC tennis correspondent Russell Fuller's analysis|
|"In a BBC interview on the eve of the quarter-final, Amelie Mauresmo said she sees no reason why Murray can't win - even if he may not be at his best until 'towards the beginning of next year' when he's 'completely fresh and ready'. Murray was very fired up during his win over Jo-Wilfried Tsonga, often pleading very emotionally with himself to raise his game. 'I haven't really made up my mind on this yet,' said Mauresmo. 'He's old enough now to know what's good for him, how he should behave on the court, what brings him energy and what maybe is taking him down a little bit sometimes. It's not going to be either saying nothing or completely going crazy on the court - he has to be in the middle somewhere.'"|
Murray has struggled to find that balance consistently in New York, as the statistics illustrate.
He needed four sets to beat Robin Haase in round one and Andrey Kuznetsov in round three, while Djokovic has rolled through his 12 sets with few alarms, but there were signs of a return to form in Murray's fourth-round win over Jo-Wilfried Tsonga.
Some heavier serving and impressive net play were backed up by returns that constantly troubled the Frenchman.
"When he's aggressive and he steps in, that's something I've always wanted to see him do," added Henman.
"When you're a little bit tired and don't fancy running quite as much as he has done in the past then sometimes you take more risks, and if he's going to do that then I think it bodes well for every match he plays.
"When he's stepping up the court and hitting his backhand down the line, attacking second serves, that's when he's playing his best, so I'd like to see more of that."
Taking on the world number one will require further improvement, however, and Craig O'Shannessy, lead analyst for the ATP and WTA, has been looking at some of the key areas that could decide the match in Murray's favour.
|Murray & Djokovic at 2014 US Open|
|Murray has played 14 sets and 140 games, Djokovic has played 12 sets and 101 games|
|Murray has spent 10hrs 4mins on court, while Djokovic has been detained for 6hrs 33mins|
|Murray's fastest serve is 136mph and his average first serve 108mph, Djokovic is 125mph/112mph|
|Djokovic has hit four double faults to 18 from Murray|
|Djokovic has hit 116 winners and 81 unforced errors, Murray has hit 175 winners and 123 unforced errors|
|Murray has won 104 points at the net, Djokovic has won 45|
|Both men have made 76% of returns|
"Murray's serve carried him to victory in the 2012 US Open final against Djokovic, the last time they played in New York, when he mainly targeted his serves out wide in the deciding fifth set. He attempted 12, made 10 and won nine - it was a masterful strategic move.
"But this year his serve is not performing nearly as well, especially compared to Djokovic's. Murray has hit 18 double faults to Djokovic's four, made 9% fewer first serves (67% to 58%) and won 7% fewer (79% to 72%) first-serve points.
"The fact that Djokovic has been broken just four times to Murray's 13 shows just how more dependable the Serb has been on serve."
Better from the baseline
"Murray's serve is not the only area of concern - his baseline play has dropped off considerably over the last two rounds. Murray won 52% of his baseline points against both of his first two opponents in Haase and Matthias Bachinger, but that dropped down to 46% points won from the back of the court in his last two matches against Kuznetsov and Tsonga.
"Tsonga is obviously a much higher-ranked player, but Murray was at 50% when he won here in 2012 and will need to have a winning percentage against Djokovic, who currently leads the tournament at 62% points won from the back of the court."
"Murray's form has ebbed and flowed but he has shown glimpses of his best tennis. In the first set against Tsonga, which he won 7-5, Murray won all nine of his approach points, 94% of first-serve points and 80% of second-serve points. His average first-serve speed was a remarkable 125mph, but by the third set that had fallen off a cliff, down to 112mph.
"Murray did win 28 of 31 points at the net for the match and is tied at fifth for the tournament with 81% points won coming forward.
"In fact, Murray may be reinventing himself before our very eyes. Only three other players in the tournament have come forward more than the Scot."
|Murray v Djokovic - last six meetings|
|2014||ATP World Tour Masters 1000 Miami - quarter-final||Novak Djokovic won 7-5 6-3|
|2013||Wimbledon - final||Andy Murray won 6-4 7-5 6-4|
|2013||Australian Open - final||Novak Djokovic won 6-7 (2-7) 7-6 (7-3) 6-3 6-2|
|2012||ATP World Tour Finals, London - round robin||Novak Djokovic won 4-6 6-3 7-5|
|2012||ATP World Tour Masters 1000 Shanghai - final||Novak Djokovic won 5-7 7-6 (11-9) 6-3|
|2012||US Open - final||Andy Murray won 7-6 (12-10) 7-5 2-6 3-6 6-2|
"Djokovic hasn't played brilliantly this summer," said Henman, the former British number one now playing on the ATP Champions Tour.
"But with two big-match players like Andy and Djokovic, with both of them having four matches under their belts, they've got the experience and there's no secrets between them.
"They've known each other and have been playing each other for such a long time that it really comes down to who plays best on the day.
"I definitely give Andy a chance, but for me Djokovic is the slight favourite."