Murray conundrum for Federer

Roger Federer admits Andy Murray is still something of an unknown quantity ahead of their semi-final clash at the BNP Paribas Open in Indian Wells tonight.

Murray boasts an enviable record against the former world number one having won five of their seven meetings.

The 21-year-old triumphed the last time they went head to head, at the Qatar Open in January and, although Federer acknowledges Murray is a tricky prospect, he is backing himself to come good when it matters most.

“He’s young, so I still have to figure him out a little bit,” said Federer, who announced this week his long-term girlfriend is expecting their first child.

“He’s changing his game as time goes by. Every time you play him he plays a bit differently. Whereas, for me, it’s different. He knows what to expect. That’s the advantage of a youngster.

“I’m aware he has beaten me more than I’ve beaten him but, on big occasions, I think I came through.”