Djokovic vs del Potro
Juan Martin del Potro played brilliantly to beat Federer yesterday, serving powerfully and precisely, and consistently putting Federer under duress with his crushing forehand. If he can replicate this form against Djokovic, he'll give himself a chance to break through the world no.1's diamond strength defence and dictate from the baseline. As ever, against the best returner in the game he'll need to serve with high percentages similar to those he produced against Federer in the final set of that match, as well as follow strong serves up with some first strike, pressing play. Their last encounter on a hard court at the US Open demonstrated just how hard Djokovic is to break down at the back of the court in long rallies, and del Potro has to force the play early on to avoid repeating the loss in which he fought valiantly but was still downed in straights. So in short, Djokovic is still the favourite, but del Potro possesses the ability and firepower to repeat his performance in the 2009 World Tour Finals. Additionally, there has been evidence to suggest there is an element of jadedness in Djokovic, who has started a couple of his matches quite slowly, especially in his 3 set win against Murray. If he starts slow del Potro has to take advantage and put the Serb on the back foot. But as we've seen for two years now, Djokovic's ability to fight back from the semblance of a defeat is so good it's unnatural. And that's likely how the match will play out - del Potro to start strong, Djokovic to come roaring back, but shoot me down for being a contrarian, this time I think the Tower will win in 3 bruising sets.
Federer vs Murray
After beating Federer at the Olympics and following it with his first Grand Slam, Murray has shed the element of doubt that he can beat his contemporaries on the biggest occasions. Despite losing the Wimbledon final to Federer he has now won 5 straight sets against him, utilising his unique game which Federer has recently struggled to deal with. Aside from a poor start against Berdych and lapses in concentration against Djokovic, Murray has looked good this week, serving strongly and displaying a positive intent to be aggressive. Federer's form has been solid, but he has at times looked fragile; the first set against David Ferrer he was fortunate not to have lost, serving at a very low first serve percentage and spared by Ferrer missing multiple break points, and against del Potro he played an atrocious tiebreaker, missing several backhands. He can't afford to be slack on the big points against Murray, who will be galvanised by his home crowd and unlike Ferrer will be all over Federer's second serve if he fails to make a sizeable number of first serves. I expect Murray to extend his winning streak over Federer in 3 sets.