We have been spoilt by the truly great tennis rivalry between Roger Federer and Rafael Nadal over the years.  By the numbers, the Swiss and the Spaniard are the most successful players in the history of the game. 

Federer has 20 Grand Slams and Nadal has 17, two clear of Novak Djokovic.

Friday's French Open semi final between the pair will be their 39th match, but the quirk at Roland Garros is that Federer has never defeated Nadal in five meetings.

33 year old Nadal is the king of the French Open.  He has won eleven titles in Paris to Federer's one.  Only Robin Soderling and Novak Djokovic have beaten him in his adopted home.

The pair haven't met on clay since the 2011 decider, one for four wins in finals for Nadal against his friend and rival. His left handed forehand is especially effective on clay against Federer's backhand.

However, Federer, who is still going strong at the remarkable age of 37, has won the last five meetings between the pair.  That run included the brilliant five set victory in the 2017 Australian Open final.

A second coming of incredible proportions has allowed Federer to pick and choose which events he plays in.  This year, he decided to go back on clay after a three year hiatus.  The only thing he has left to achieve is to beat Nadal in Paris and now he has his chance.  The duo have only lost a set each en route to the last four.

It's almost unbelievable that Federer and Nadal are still going strong in Grand Slams, 11 years after what may see as the greatest match of all time, the 2008 Wimbledon Final.  That was when Nadal's never say die spirit edged Federer's natural brilliance.

Andy Murray's body has come under pressure, and one would have to think there will be a significant void when this greatest era of tennis draws to a close.  Who is coming through?  Who has the grace of Federer, the iron will of Nadal?  Which players will make the sport epic again?  It's hard to see it at the moment.