London - Andy Murray could beat Roger Federer on Thursday and crash out of the ATP World Tour Finals or lose and go through to the semi-finals - such is the conundrum he faces.
However, the 27-year-old home favourite is glad just to still be in contention after Tuesday's 6-3 7-5 defeat of big-serving Canadian Milos Raonic.
That victory, following his defeat by Kei Nishikori in Group B on Sunday, means all scenarios are possible going into the final round-robin matches, although a straight-sets win for world number six Murray would leave him in good shape.
“Well, for (Federer) I think there's a very good chance that he's going to go through regardless of the results,” Murray said of his 23rd career meeting with the Swiss who is on top of Group B after two comfortable victories.
“For me it depends on the winner of the Nishikori/Raonic match. If Kei wins, then I need to beat Roger, it depends on the scoreline of that match with Kei and Raonic.
“If Raonic wins, then I know that all I need to do is win the match against Roger and I'll be through.
“I'm not going to know that until I get ready for the match because I can't predict the future.”
Murray and Federer are locked at 11-11 in head-to-head clashes, although Federer has won all three of their meetings at the Tour Finals since it moved to London's 02 Arena.
Federer also beat Murray in the 2012 Wimbledon final, although Murray did get revenge when he beat the Swiss to win the Olympic gold medal on Wimbledon's Centre Court.
“It will be obviously a very difficult match,” Murray said. “But it will be an exciting match. A good one to be part of.
“We've had some very good matches over the years. I hope on Thursday it will be the same.
“Hopefully I can get through the group and keep going. If not, playing against Roger is a good way for me to finish the year, as well.
“There's a lot of positives for me going into that match. It's nice to go into Thursday with an opportunity to go through. I'm looking forward to it.”
Should Murray and Nishikori both win in straight sets the calculators would have to come out to decide who goes through.
Murray will at least know the situation before he walks on court as his match with Federer is scheduled for Thursday's evening session, after winless Raonic and Nishikori face off. – Reuters