It seems almost unthinkable: A seventh French Open title by his 26th birthday? Seven? It could happen. Rafael Nadal is that good on the red clay of Roland Garros. If he wins the trophy on June 10, the swashbuckling Spaniard would eclipse Bjorn Borg and put to rest for good the question of who is the best clay-court player of all-time.

By nearly every other statistic, Nadal already has claimed that honor. Since 2005, he is an astounding 220-9 on clay, a .961 winning percentage. He is 46-1 at the French Open. During his career, he has won 93 percent of his clay matches, compared with 86 percent for Borg.

And it isn’t just in Paris where Nadal conquers the dirt. He has won eight Monte Carlo titles, seven Barcelona Opens and six Italian Opens. Thirty-five of his 49 titles have been on clay.

“To me, he’s the greatest clay-courter ever — already. To me, what he’s chasing is trying to chase down Roger [Federer] and get into the conversation of being the greatest of all-time, and the greatest of this era,” ESPN analyst Patrick McEnroe said. “And if it wasn’t for a guy named [Novak] Djokovic doing what he did last year, Nadal might be knocking on the door of doing that.”

Djokovic, the top-ranked Serb and No.1 seed at the French Open, beat Nadal in seven consecutive finals last year. He is the defending champion of Wimbledon, the U.S. Open, and Australian Open. If he can somehow win the French, he’ll become the first man in 43 years to hold all four Grand Slam titles in a 12-month period. Although it is not a true Grand Slam because it doesn’t fall in a calendar year, it is quite a feat.

The underdog?

But Djokovic concedes he is the underdog on clay, despite his ranking.

“He is always the favorite, even if I win against him seven times,” Djokovic explained after losing to Nadal 7-5, 6-3 at the Italian Open final on Monday. “He is the best player in the world on this surface.”

Other than a speed bump on the controversial blue clay of Madrid, where an irritated Nadal lost to Fernando Verdasco, he has dominated this clay season and regained any confidence he might have lost through his struggles with Djokovic. He won titles in Barcelona, Monte Carlo and Rome, and beat the Serb in the final of two of those.

Last year at this time, Djokovic had beaten Nadal in the Madrid and Rome finals, and went 41-0 before losing to Federer in the French Open semifinal. This spring, order has been restored and No. 2 Nadal is the man to beat on the red stuff.

“Hopefully, I will keep playing like this,” Nadal said after beating Djokovic in Rome. “When you lose, you play with doubts.”

On the women’s side, 30-year-old Serena Williams is dispelling any notion she doesn’t like clay courts. She is 17-0 on the dirt this year and lost only two sets during the streak. She has beaten No. 1 Victoria Azarenka and No. 2 Maria Sharapova by identical scores of 6-1, 6-3. And though four women are ahead of her in the world rankings, and her only French Open title came a decade ago, she arrives at Roland Garros as a favorite along with the top two players and defending champion Li Na.

“I absolutely love clay,” Williams said after winning in Madrid. “It’s really a myth about me not liking clay.”