Rafael Nadal and Novak Djokovic will renew rivalry in Wimbledon semi-finals

Nadal, 32, and Djokovic, 31, meet in a highly anticipated Wimbledon semi-final at about 16:30 BST on Friday.
They have met on 51 previous occasions, but not at this stage of a Slam since the 2014 French Open semi-finals.
The winner will play either John Isner or Kevin Anderson in Sunday's final.
Spain's Nadal and Serbia's Djokovic have won 29 Grand Slam titles between them, including five previous victories at SW19.
The pair have only met twice at Wimbledon, Nadal winning their 2007 semi-final when Djokovic retired hurt, the Serb gaining revenge in the 2011 final.
"There is no one other match in the history of tennis that has been played more than our match. That's a big thing," said second seed Nadal.
"We always played in important stages, important places."

The most enduring rivalry
While Nadal's rivalry with Roger Federer may be considered as the most engaging, it is the Spaniard's rivalry with Djokovic which is the most enduring.
The pair have produced some of the greatest matches ever seen - which include memorable Grand Slam finals and career-defining victories.
They have met in:
7 Grand Slam finals
4 Grand Slam semi-finals
17 other tour-level finals
13 other tour-level semi-finals
1 Olympic semi-final
Djokovic leads 26-25 in their head-to-head, dominating in recent times with seven victories in the past nine matches.
"It is always a big challenge facing Novak," said Nadal.
"He is one of the more complex players that I ever saw in our sport. It is always a big test.
"You know that you can't win against him if you don't play very well."
Three of the best Nadal-Djokovic matches

Australian Open final - January 2012
Djokovic wins 5-7 6-4 6-2 6-7 (5-7) 7-5
A match which has gone down in the record books as the longest Grand Slam final, lasting five hours and 53 minutes - and finishing at 1.37am - before Djokovic prevailed.
French Open semi-final - May 2013
Nadal wins 6-4 3-6 6-1 6-7 (3-7) 9-7
After seven weeks out with a serious knee injury, many doubted if Nadal would regain his crown as the 'King of Clay'. Playing Djokovic was the sternest test and he came through a dramatic five-setter dubbed the greatest clay-court match of all-time by Bjorn Borg and John McEnroe.
Madrid Open semi-final - May 2009
Nadal wins 3-6 7-6 (7-5) 7-6 (11-9)
Djokovic came close to beating Nadal for the first time on clay, only to see the Spaniard save three match points before winning one of the greatest and - at four hours and two minutes - longest three-set matches in history.