Roger Federer (SUI)  vs. Novak Djokovic (SRB) : Who will the roof favor? As I type the rain is falling steadily here at the All England Club and the roof over Centre Court has been closed. Federer is a notoriously good indoor player, though let's face it, he'd probably be notoriously good on quicksand as well. The closed roof should help his serve, but then again Djokovic has played under the roof here at Wimbledon for three matches and he says he feels like it helps his return. So maybe it's a push? If so, it's hard not to favor Djokovic here. He's won their past three meetings and four of the past five semi-finals at a Slam. But this is their first clash at Wimbledon on a surface that rewards everything that Federer has: an aggressive mindset, precision serve, and swashbuckling forehand. A win here would move him one match away from knocking Djokovic from the top spot and regaining the No.1 ranking. With no Rafael Nadal waiting for him in the final, I think that will be the extra motivation he needs to pull off the win.
Pick: Federer in four sets.
Did you know... this is Djokovic and Federer's 11th meeting at a Slam, putting them in first place for the most matches played at majors.
Andy Murray (GBR)  vs. Jo-Wilfried Tsonga (FRA) : As Murray Mania sweeps the nation, could this finally be the year that Murray breaks through to become the first British man to win a Wimbledon semi-final since Bunny Austin defeated Henner Henkel in 1938. He has a 5-1 head-to-head record against the Flying Frenchman, beating him on grass twice, once at Wimbledon and once at Queen's Club last year. But we know what kind of tennis Tsonga can play on grass, as his serve and pure athleticism combine for a dynamic and unpredictable game. He'll play an attacking game against Murray, getting to the net as much as possible to finish off points. If he has a good serving day, this could be a tense one for Murray.
Pick: Murray in five sets.
Did you know... Henner Henkel, the last man to lose to a Brit in a Wimbledon semi-final, died in the Battle of Stalingrad.