At 35 of the past 37 grand slam tournaments, a member of tennis’ so-called Big Four – Roger Federer, Rafael Nadal, Novak Djokovic and Andy Murray – won the championship.

The quartet’s dominance is even more pronounced at Wimbledon: They have collected the last 11 titles, including seven for Federer.

For nine years in a row, at least two members of that group participated in the All England Club semi-finals, a streak that continues Friday, when the top-seeded Djokovic faces No 11 Grigor Dimitrov and No 4 Federer meets No 8 Milos Raonic.

The contrast in experience and accomplishments is striking.

Federer, 32, has 17 major titles and will be playing in his 35th major semi-final.

Djokovic, 27, has won six majors. This is his 23rd semi-final.

Raonic and Dimitrov are both 23 and making their debuts at this stage of a major.

“You can’t really outrun time, in one way. New guys got to come up and they’ve got to step up. We’ve been doing better and better, especially throughout this year,” Raonic said about a potential transition at the top of the sport.

“It’s good to be a part of it. It’s nice to see that sort of human side to those four guys.”

Here are five things to watch in today’s semi-finals.

Ominous Federer

A year after exiting in the second round with a bad back, Federer is again playing dominating grass-court tennis.

Since winning his first grand slam title at Wimbledon in 2003, though, Federer has never gone this long without reaching a major final – it has been two years since he won at the All England Club in 2012, which was also the last time he featured in a final.

Djokovic’s drought

The world No 2 has lost in the final match at three of the past four major tournaments – against Murray at Wimbledon and against Nadal at the US Open last year, and against Nadal at the French Open last month, meaning the 2013 Australian Open is the most recent of his six titles.

After working for years to break through the Federer-Nadal duo, now Djokovic is part of the elite, trying to hold off new challengers.

“We have these youngsters coming up, fearless on the court, hitting the ball, not caring who is across the net,” Djokovic said. “It’s good. It gets more attention to new faces and to [a] new wave.”

Dimitrov’s momentum

Greatness has been expected of him for years, and he long ago was given the nickname “Baby Fed”, as in Federer, because of a similar all-court style and a smooth, one-handed backhand.

Dimitrov is the only man who has won titles on all three court surfaces in 2014, and he is on great form at present, having won his past 10 matches on grass, culminating in a defeat of defending champion Murray in straight sets on Wednesday.

“He moves well; he’s a very good athlete; he has variety in his game, which helps him play on all of the surfaces,” Murray said. “He’s a talented guy.”

Raonic making history

At a towering 1.96 metres, the Canadian delivers one of the most-feared serves in tennis. “It keeps him in the match,” Federer said.

Raonic lost in the second round in each of his first three trips to Wimbledon, but now is the first Canadian man in 106 years to reach the semi-finals.

It continues his good run of form in 2014, during which he reached the quarter-finals at the French Open last month for the first time before losing to Djokovic.

How they match up

Djokovic is 3-1 against Dimitrov. Both are terrific movers and retrievers, which should make for lengthy exchanges when they meet on Centre Court.

The points should be shorter in the other semi-final. Federer is 4-0 against Raonic, but the 23 year old did not sound intimidated in the least about the prospect of facing off against the most successful man in tennis grand slam history.

“I’m not playing the seven-time Wimbledon champion,” he said. “I’m not playing a 32-year-old man. I’m not playing a father of two sets of twins . I’m not playing the guy that’s won whatever he’s won, which I could probably list quite vividly. I’m playing a guy that is standing in my way of what I want to achieve.”