What makes Rafael Nadal almost unbeatable on clay?

Whenever he steps on to a court at Roland Garros, his arrival is announced over the PA system with words to the effect of: "The king has arrived!"

Yet again, Rafael Nadal is the undisputed favorite at the French Open, the second Grand Slam tournament of the year after the Australian Open.

Should the king triumph again in 2018, it would be the Spaniard's 11th title in the French capital. However, even if he fails this time around, Nadal has already established himself as the best clay court player of all time. The 31-year-old has a scarcely-believable record of 79 wins and just two defeats in Paris. So what makes the 31-year-old so dominant on clay?

Incredible topspin

The "secret" to his success is a mixture of his physical fitness, metal toughness and a hitting technique which is second to none. Nadal's forehand in particular is feared by his opponents on clay. The forehand is many players' best weapon, but Nadal's is simply world class.

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What most sets him apart from all the others is the amount of topspin that he is able to generate on his forehand – up to 6,000 revolutions of the ball on a single shot. Nadal's average spinrate is around 3,200 revolutions, while his biggest rival on the ATP Tour, Roger Federer, averages around 2,700 revolutions.

Pete Sampras played with far less spin

Top ranked men's players from earlier generations, such as Pete Sampras, generated just 1,700 revolutions per shot on average. And no player currently on the ATP Tour can come anywhere near the topspin that Nadal is able to generate.

Nadal is capable of doing this due to his extremely muscular body and an unusually fast swing, which allows him to put much higher-than-average amount of energy into his shots. Not only that, but when he winds up he swings his racket from over his head, giving his shots additional force.

This forces his opponents to play the ball much higher than usual, jarring them out of their comfort zone. Due to the enormous topspin on Nadal's shots, they also come at his opponents at an unusually high speed. These factors cause the Spaniard's opponents to play more defensively than they'd prefer, severely limiting their offensive shots and match plans. They find themselves forced only to react instead of taking the play to Nadal.

Nadal becomes stronger when faced with tough situations

Only opponents who also possess exceptional technical skill such as Federer, Alexander Zverev, or Novak Djokovic are able to compete with Nadal on clay. On the particularly hard and fast courts of Paris, though, they too seldom stand a chance against him.  

In addition to his exceptional shot-making skills and outstanding physical fitness, Nadal possesses the sort of mental toughness that allows him to maintain his concentration even in the most difficult phases of a match.  In situations in which many might buckle under the pressure, Nadal is able to remain focused – and mercilessly exploit any doubts or hesitation on the part of his opponent.

Another constantly impressive facet of his game is the way he is able to extract himself from difficult situations with bold, offensive shots. His mental strength is a gift that makes him the envy of most players on the Tour, and it's something that can't be taught or learned.

Nadal has arrived in Paris in excellent form, having won on clay in Monte Carlo, Barcelona and Rome – his only blip coming in a quarterfinal defeat at the hands of Austria's Dominic Thiem in Madrid.  So assuming he stays healthy, it seems a good bet that the 2018 French Open will end with Nadal hoisting the men's singles trophy high – for a record-extending 11th time.