Murray's game gives Federer trouble, there's no doubt about it. He gets a lot of balls back and flusters him the same way Nadal does. Djokovic tends to play Federer more agressive which Federer likes because if he's on his game he can hold his own more and it is a rhythm he likes more.
There are interesting things about the H2H that's not just a lot of excuse making.
Of course they have only played 2 matches on grass, both as late as this year, and have never played a single clay match which is surprising as Murray can make clay semis.
Murray gave Federer his only pre final loss in 2006 in the first match at Cincinatti.
Murray at one point led 6-2 (in 2009) but since then Federer has managed to have more success and keep the H2H fairly even, level at one point this year, never more than 3 behind. So this tells us that Federer has become better at dealing with Murray.
Federer at one time lost from a set up in best of 3, 4 times in a row vs Murray.
Murray is 9-6 in best of 3, and Federer is 3-1 in best of 5.
In best of 3 matches Murray has won 5 that went the distance, and 4 in straight sets. Federer has won 1 that went the distance and 5 in straight sets. Seems Murray's odds improve a lot when it goes to 3.
Interestingly enough, the last 3 set match that went to 3 sets was the WTF 2009. Since then there have been 6 best of 3 matches all won in straight sets (3 by each) and including all matches, in the last 9 matches Federer and Murray have played against each other, only one has not been straight sets (Wimbledon final) that's 9 matches, 4 straight set wins each and one 4 set win by Federer. So generally the trend has been whoever wins the first set wins in straights. And no real edge to either player, you never know who willwin but whoever does usually (in recent history) wins fairly easilyin score at least.