Novak Djokovic (SRB)  vs. Marin Cilic (CRO) . The #1 seed has been playing excellent tennis against high-quality opponents like Radek Stepanek, Gilles Simon and Jo-Wilfried Tsonga. Djokovic has never lost to Cilic in nine previous meetings, but in their tenth meeting (first on grass) he faces an improved and re-committed Marin Cilic, now coached by former Wimbledon champion Goran Ivanisevic. Cilic is brimming with confidence himself, since he took out 2010 Wimbledon finalist Tomas Berdych in the 3rd round. I do believe that Cilic believes that he can win this match, and he will probably will one and possibly two sets, but I find it extremely unlikely he will be able to win three against the 5-time major champion. PREDICTION: Djokovic.
Andy Murray (GBR)  vs. Grigor Dimitrov (BUL) . These two have played each other four times on tour and even though the defending Wimbledon champion leads their head-to-head 3-1, the last time these two met (on the hard courts of Acapulco) the younger player prevailed. Dimitrov survived a tough 5-set battle with Aleksandr Dologopolov but otherwise has been moving through the draw smoothly. He even established his grass court bonafides by winning a Wimbledon warm-up tournament in Birmingham this year. Dimitrov is playing in his first Wimbledon quarterfinal while Murray is playing in his seventh. Since achieving any British player's career dream by winning Wimbledon last year, Murray has not even reached a final anywhere on tour. However, now that he is back at the All-England Club he has yet to drop a set. I suspect that streak will be broken during this match, but that will not prevent Murray from reaching his 6th consecutive Wimbledon semifinal. PREDICTION: Murray.
Stan Wawrinka (SUI)  vs. Roger Federer (SUI) . These two countrymen (and good friends) have met 15 times before with Federer only losing twice. Although, like the Murray-Dimitrov match-up, it is significant to note that their most recent meeting (in the Monte Carlo Masters Final) was won by the underdog in their rivalry. The two have met three times in major tournaments and Federer has won all of these meetings but all of these matches were played before Stan won his maiden slam this year in Melbourne (over Federer's arch nemesis, coincidentally) and none on grass. Federer is playing some vintage grass-court tennis; he has yet to have his serve broken in the tournament and thus has not dropped a set. Wawrinka has not only dropped a set, he was actually pretty lucky to win two tiebreak sets against the excellent grass-court tennis of Feliciano Lopez in the 4th round. I would be surprised if there are any tiebreaks in this meeting, but I do think there will be breaks of service. Federer is playing for history: if he wins he will extend his own record of major semifinals to an astonishing 35, and thus give himself an opportunity to reach an even more astonishing 25 major finals and perhaps win his 18th major. PREDICTION: Federer.