French Open 2017: Is Rafael Nadal back to his very best?

Rafael Nadal won nine French Open titles between 2005 and 2014

Rafael Nadal has rediscovered his game and his aura, and now he looks ready to take his title back.

The Spaniard, who plays Dominic Thiem in the semi-finals on Friday, is just two wins from a record 10th French Open - 'La Decima' - and his first since 2014.

"It's starting to be the way it was," Carlos Moya, who joined Nadal's coaching team in December, told BBC Sport.

"That was one of the things that we wanted back, that the opponent feels he's playing Nadal again and if they want to beat him, they're going to have to work really hard."

They might have to work hard but thus far Nadal's opponents haven't had to spend much time on court.

The Spaniard, 31, has been getting them out of there in close to 90 minutes per match, reaching the semi-finals for the loss of just 22 games in five matches - the fewest games lost to this stage of a Grand Slam since best-of-five matches were introduced.

Twelve months ago, Nadal was forced out of the tournament through injury, and two years ago he was brushed aside by Novak Djokovic. In 2017, he has looked unstoppable.

Rafael Nadal won his first French Open title in 2005

Forehand fires Nadal back to the top

There is no question Nadal has rediscovered his mojo on the clay, but opinion is divided over whether he is back to his very best.

His new coach believes he's not far away.

"I think he's really close to 100%," said Moya. "He's played some matches this year when his level was really good.

"It's hard to compare with the old Rafa, but I think if he's not at the same level, he's close to that."

Nadal might be the king of clay but his game looks increasingly like hard-court tennis on the red dirt.

Successful in a stunning 76% of points behind second serves, and 69% of first serves, Nadal is then winning 62% of his points in under four shots, as opposed to just 15% in rallies of more than nine strokes.

And it is his most famous shot that once again dominates Roland Garros.

"The wheelhouse of the Nadal renaissance has been his forehand," says Craig O'Shannessy, strategy expert for Wimbledon, the Australian Open and the ATP World Tour.

"He has hit 61 forehand groundstroke winners to the semi-final, with the majority hit straight down the line."

• 72% of Nadal's winners have been hit wide past the opponent's forehand. 28% went to the backhand side.

• 70% of those winners to the opponent's forehand side have been hit straight down the line.

• 57% have come when he is serving.

• 56% have been struck with Nadal standing inside the baseline.

• 30% have come as an approach shot as he moved forward to finish the point.

The image of Nadal might be of long, grinding rallies from deep behind the baseline, but the reality in 2017 is that plan A is stepping in, opening up the court early, running around his backhand and cracking a forehand winner.

Physically fit, confidence returns

Nadal has missed five Grand Slams through injury, and was forced out of last year's French Open with a wrist problem which saw him also miss Wimbledon and curtail his season after the US Open.

The punishing nature of his baseline game led many to speculate from the early years that his would be a much shorter career than those of his rivals.

However, rested and rehabilitated, he returned at the start of 2017 to reach his first Grand Slam final since 2014 in Australia, before once again dominating the clay-court season.

"I think everybody is a little bit surprised by his performances again, but when he recovers physically 100%, he gets the confidence to fight," said former French Open champion Juan Carlos Ferrero.

"I think being physically fit is the key to his performances right now.

"He had no injuries in the last six months and I think it's very important for him to feel like this.

"He's also recovering balls the same as before, impossible points that in the last year maybe we didn't see from him, because he couldn't move as well."

Moya helps smooth transition from Toni

Former world number one Carlos Moya has been part of the Rafael Nadal camp for seven months

One of the great coach-athlete relationships in sporting history will end this year when Toni Nadal - 'Uncle Toni' - steps away from life on the tour.

The 56-year-old, who made the decision to change a natural right-hander to play left-handed, will return to the family's home of Majorca to concentrate on running his nephew's tennis academy.

His departure lends an extra dimension to Nadal's quest for another title at Roland Garros, the place where he and Toni began an extraordinary story 12 years ago.

"He always says one of the biggest things for him is to have his family very close," said Ferrero.

"So to have his uncle as somebody who is there all the time in important moments, bad times, injuries, everything - of course Toni is one of the important people he'll always have in his life."

The succession plan is well under way, however, with former French Open champion Moya brought on board in December.

"It makes me very proud," said Moya. "I know who I am with, how big in the history of this sport he is, so I try to make the most of every day I have with him.

"It's been a learning experience for me."

There were widespread calls for a change in the Nadal team when he went through his prolonged slump, and Ferrero believes Moya's introduction will bring a new dimension to the coaching set-up.

"To have someone on the team like Carlos, who knows all the time what is going on in the match because he played on the tour, I think it's very important to have someone who can then go to the locker room and talk about the match," added Ferrero.

"Rafa can talk with Toni as well but Carlos went through all the matches like he did, so it's something Rafa didn't have before."

Nadal still feeling the nerves

You might think that nine titles and a 77-2 career record would make Nadal stride through the gates of Roland Garros with at least a hint of a swagger.

"I won here nine times," said the Spaniard, "and every year that I won I was unbelievably happy, but every year that I came back, I was unbelievably nervous."

If Nadal carries that feeling with him as a matter of course, the looming prospect of making almost unfathomable tennis history must be an added burden.

Victory in Sunday's final would make him the first player to win any of the Grand Slam titles 10 times in the open era, and only the second ever after Margaret Court's 11 Australian Open wins.

"La Decima? No, no, no," said Moya, when asked if it was a subject of discussion in Team Nadal.

"You know that it's there but it's coming more from the press and the people and the fans, than from Rafa and his team.

"We know it's there but we believe also it can add some extra pressure, so we don't talk about that.

"He probably does feel more pressure at this time of year, especially here.

"Every year he's coming, he's defending champion most of the time, or if not he knows it's the tournament he has the biggest chances to win, so there's always some extra pressure here."

Is a 10th title inevitable?

Nadal (right) has extended the record he set in 2014 for most Roland Garros semi-final appearances in the open era (10)

There have been plenty of people keen to re-anoint Nadal as the king of clay based on his resurgence this season, but the real tests still lie ahead.

The average rank of his opponents so far at Roland Garros has been 39, with Roberto Bautista Agut the highest at 18 in the world.

Now comes a step up against Thiem, the young Austrian who inflicted Nadal's only clay-court defeat of 2017 with a stunning performance in Rome.

Get through that, and he faces a final against world number one Andy Murray or former champion Stan Wawrinka.

So is a Nadal victory inevitable?

"It's difficult to say," said seven-time Grand Slam champion John McEnroe.

"That's why I wanted to see him and Novak play in the semis - we could see is he really playing better than ever?

"Certainly he's intimidating, there's no doubt, and he's the guy to beat. But I don't think it means it's over quite yet."