World number one Any Murray was the first person to admit that he most certainly will not win Wimbledon if he performs like he did during his first round defeat to Australian Jordan Thompson at the Queen's Club this week.

Murray's love affair with the famous grass surfaces at SW19 looks like it could potentially turn into a bit of a nightmare this year with the Scot experiencing one of the worst slumps in his life, coming off the back of an incredible 2016.

Murray has won just the one tournament this season, and, building up to the third Grand Slam of 2017, it has become clear that the 30-year-old is in danger of relinquishing his spot at the top of the world rankings.

So how is Murray still number one after what could be considered one of the worst seasons of his career?

The Briton has been dumped out in the first round of three tournaments this year and many are questioning how he has clung on at the top.

The ATP (Association of Tennis Professionals) uses a rolling 12-month points system to collate their weekly player ratings.

It calculates total points won from the past 19 tournaments over the previous year. Those tournaments include the four grand slams, eight mandatory ATP World Tour Masters 1000 tournaments, the World Tour Finals and the best six results from all ATP World Tour 500, ATP World Tour 250, ATP Challenger Tour and Futures Series tournaments.

Instead of a player starting the season on zero, players can collect points from tournaments they were unable to compete in or tournaments in which they suffered early exits last year.

Players can, therefore, lose points if they do not perform as well as they did the previous year and this is why, anything other than a win at Wimbledon, will see Murray lose ranking points.

With a rampaging Rafael Nadal breathing down his neck, Murray will need to win at Wimbledon, or he could lose a chunk of ranking points while Nadal can only gain points having not competed at the All England Club last year.

For Nadal, this could not be more of a perfect situation. A win at Wimbledon will see him to the top of the rankings, regardless of where Murray ends up, while the two-time champion will be left to rue what has been quite frankly a terrible year.

Another worry for Murray will be Stan Wawrinka, who should things go his way, is also in a position to unseat Murray from the top spot in London. Wawrinka will have to win and hope that Murray is knocked out in the early stages of the championships but it is a possibility considering the current form of both men. Wawrinka, who was dumped out in the second round last year, has the chance to accumulate a decent points haul with a good run at the All England Club.

Another player enduring a bizarre slump in form is Novak Djokovic, who will simply be concentrating on returning to something similar to his best form during his warm-up event at Eastbourne. It is still possible for Djokovic to move up to world number one, but he would need to win outright, and hope that Wawrinka, Nadal, and Murray all suffer early exits.

For the veteran Roger Federer, the top spot is simply out of reach for now. Federer has only competed in five events this year, and can only go as high as third place with a good run at his beloved slam.

However, with points to defend later on in the year, it would not be surprising to see Federer steal a march on his rivals for the title of the best in the world.