It’s men’s semi-final day at Wimbledon today, and two fascinating matches are in store.

Federer versus Djokovic has become a regular contest at the semi final stage of a grand slam tournament, with the pair having met eight times in the last four of one of the majors.

Djokovic holds the advantage of having won five of those encounters, but today’s match will mark the first time that the two players have faced each other on grass. That makes it a difficult match to predict with Roger Federer, perhaps the greatest grass court tennis player ever, performing much better this year than in either of his past two showings at the All England Club.

As well as a place in the final, both men are contending for the number one ranking in the world, with Federer set to take top spot if he can lift his seventh Wimbledon title.

The winner will face either Andy Murray or Jo-Wilfried Tsonga, and anticipation for the second of the men’s semi finals is every bit as great.

Neither of the two players involved have a grand slam title to their name, and both will sense an opportunity to put that right by the end of the week.

Andy Murray takes part in his fourth successive Wimbledon semi and while he may be relieved not to have to face Nadal this year, he’ll need no reminders of what happened in 2009 when, after seeing Nadal withdraw from the tournament due to injury, he went on to face Andy Roddick in the last four. Murray was the favourite but it was Roddick, the number six seed, who triumphed in four sets on the way to a narrow loss to Federer in the final.

Many will again consider Murray to be the favourite as he takes on Tsonga, but the Frenchman poses a genuine threat to the prospect of a first British finalist in the men’s event since 1938.

Tsonga’s ability is in no doubt and there are signs that a grand slam title may not be far away if he continues to progress. Only last month, Djokovic found Tsonga almost impossible to live with for a large part of their clash at Roland Garros, and Murray himself will recall how tough an opponent Tsonga can be, having faced him in a quarter-final at Wimbledon only two years ago.

I was in the crowd at Centre Court on that day and for much of the opening two sets, Tsonga was virtually unplayable. Home advantage certainly helped Murray, but still he was on the verge of finding himself two sets down.

Tsonga, serving with a 5-4 lead in the second set tie-break, chose the most unfortunate moment to drop points on his serve and having handed the momentum back to his opponent, it was Murray who pounced to level the match at one set all.

From that moment on, Tsonga looked beaten and there was little sign of any fight or determination to regain an advantage in the match. Having been the better player in each of the first two sets, he was swept aside with ease over the next two, both finishing 6-2 in Murray’s favour.

For me, that match perfectly summed up Jo-Wilfried Tsonga and illustrated the difference between the top players, and those who are just behind. Where competitors such as Nadal, Djokovic and Murray can often find something extra and find a way to win even if circumstances don’t look to be in their favour, there are other players who have the ability to compete with the very best, but struggle to find the extra mental strength needed to fight their way out of a corner.

If Tsonga can find a way to maintain the level of tennis he is capable of for more than just a set or two, I think he’ll have too much for Murray. He’s in good form, is improving with each year, and having reached the semi final at Wimbledon for the first time last year, will be looking to go one better this time around.

But that’s a big if, and if Murray gets on top in the early stages, or the match is a close fought affair that goes to four or five sets, then I couldn’t see anything other than a Murray win.

Whatever does happen, the two matches promise plenty of drama – and on Wimbledon semi final day, you wouldn’t have it any other way.