Roger Federer Unbreakable Against Andy Murray in Wimbledon Semi-Final

Ten years now these two have been playing each other. It is a rivalry running back to a match in Bangkok, October 2005. That one, like this, was settled in straight sets. But in between there have been many brilliant matches.

There is an old story about two officers in Napoleon's Army, Dupont and Fournier, who fought a duel when one was made to deliver a disagreeable message to the other. There was no winner and so, each being equally stubborn, they fought again the very next time they met. This time they were interrupted, so again there was no clear conclusion. A third meeting produced a third duel. The feud re-ignited each time they encountered each other ever after. (Federer Downs Murray to Set Up Title Clash vs Djokovic)

This went on - no joke - for three decades. They fought 30 times, on horseback and on foot, with swords and with pistols, on cobbled streets and grassy fields. They came to know each other's styles so well that they invariably fought to a standstill - until the day Fournier finally missed, twice, and Dupont had him at gunpoint. (Wimbledon Centre Court Mesmerised by Federer)

Murray and Federer are not quite there yet. This was their 24th match. They have played on hard courts and grass courts, in Cincinnati, Dubai and New York, Madrid, Doha and Shanghai, Sydney, Toronto and Indian Wells.

And of course, at Wimbledon, the scene of their two most famous matches, back in the summer of 2012, when Federer won one, at the Championships, and Murray the other, in the Olympic final. (Djokovic in Way of Wimbledon History Bid)

It is not the most prolific rivalry in men's tennis - Novak Djokovic and Rafa Nadal have played each other 44 times. But it is one of the hardest fought. Going into Friday's match, Federer had won 12 times and Murray 11. There have been long stretches when each man has held the upper hand. Murray won four in a row in 2008 and 2009, as has Federer in 2014 and 2015.

Just like Dupont and Fournier they now know each other so well that neither has many surprises left to offer the other. Each knew what to expect in this semi-final, as did most people watching. Federer would try to control the game with his serve and his forehand, would be quick and keen to come to the net to try to close points down and would also look to attack Murray's weak second serve. Murray, on the other hand, would want to draw Federer into long cross-court rallies with his backhand and use the lob which has won him so many points already in this tournament. So Murray knew what was coming. Not, it turned out, that the knowledge made it any easier to face.

At the age of 33, Federer is playing almost as well as ever. Certainly, Murray said, "that's definitely the best he served against me". In the first round at Halle back on 15 June Federer was pushed close by Philipp Kohlschreiber. In the end he won 7-6, 3-6, 7-6, after being 5-3 down in the final set. But late in the match something clicked.

Roger Federer reacts after a point vs Andy Murray.

© AFP

Ever since then his serve has been in a rare and record-breaking rhythm. After that he played Ernests Gulbis and Florian Mayer, Ivo Karlovic and Andreas Seppi and was not broken once. Then at Wimbledon he played Damir Dzumhur, Sam Querrey, Sam Groth and Roberto Bautista Agut. Again he went unbroken.

In his quarter-final against Gilles Simon Federer broke Wayne Arthur's 16-year-old record for holding serve in the most consecutive games. Arthur had done it 111 times. Federer's streak got to 116. And then, finally, he was broken.

Just the once, and, Simon said afterwards, it took "the perfect game" to do it. And of course, Federer immediately broke back. The point is: right now Federer's serve is almost unassailable. The problem Murray faced, the problem Djokovic will face, is, how, exactly, does one go about beating a man who is unbreakable?

As Murray said afterwards, he played OK, better even than that makes him sound. "I didn't actually play a bad match," Murray said. "I played pretty well." But he never came close to finding an answer to that one crucial question. In the first set 85% of Federer's first serves were in, in the third 81%. Federer has now played 10 matches against 10 men, two of them, Simon and Murray, among the very best returners in tennis, and he has been broken only once.

Murray had an opening early on, in the very first game, a break point earned with an exquisite lob and a fine forehand down the line. But the next return went into the net, followed by an error and a service winner.

The chance was gone and he did not get another. Federer's grip on the match got tighter. Murray, on the other hand, seemed always to be scrambling to find a footing. Federer made it all look so easy.

The difference was never better illustrated than late in the second set. In the 10th game Federer had five set points. Murray scrambled furiously, saved each and every one, then finally won the game with an ace. In the next game Federer won to love. One game took a little under 10 minutes, the other a little more than 60 seconds.

Then the pressure was all back on Murray again. This was the day that Murray, just like Fournier, ended up looking down the barrel of his opponent's loaded gun and knew that, this time, there was nothing he could do. The other man had won.