http://news.bbc.co.uk/sport1/hi/tennis/8047928.stm By Piers Newbery "Is there a tougher challenge in sport than seeing Rafael Nadal on the other side of the net on a clay court? The 22-year-old Spaniard heads to the French Open on Sunday unbeaten on the red dirt of Roland Garros and an apparent dead cert to win a record fifth straight title. Closest rival Roger Federer describes Nadal's achievements as "phenomenal", telling BBC Sport: "He's dominating clay in an unbelievable way right now." Federer gave the rest of the field hope by beating Nadal in the Madrid final last week, ending the Spaniard's unbeaten run through Monte Carlo, Barcelona and Rome. But the Swiss admitted afterwards: "I don't think he's going to take any damage away from this. I'm sure he's going to be rock solid in Paris again." Andy Roddick, who lost to Federer in Madrid, said: "Rafa is still the best clay player in the world. I guarantee you Roger would tell you the same thing. Rafa is the favourite for the French." Rusedski on the 'big four' of men's tennis If the statistics are anything to go by, the other 127 men in the draw really are there just to make up the numbers. Since 2005, the year he first won the French Open, Nadal has won 150 matches on clay and lost just five, and the defeat by Federer ended a 33-match winning streak. Nadal has won all 28 matches he has played at Roland Garros, 21 of them in straight sets, and has a 45-0 record in best-of-five-set matches on clay. Last year he was more dominant than ever in Paris, winning all 21 sets he played, with only Novak Djokovic extending him as far as a tie-break. Before Federer's win in Madrid, 2003 French Open champion Juan Carlos Ferrero had been the last man to beat Nadal on his favourite surface in Rome last May. "Rafa had an injury in his toe and I was having some trouble with my abductor muscle," says the former world number one. "I was able to play aggressive the whole match and I think I did a good job. It was a combination of playing aggressive tennis without making too many mistakes." Aggression appears to be the key to any sort of success against Nadal on clay, and Djokovic in particular has extended the world number one in recent weeks without managing to close out a win. Comparing the 'big four' in 2009: Asked how to tackle the Majorcan, Albert Costa, the 2002 champion at Roland Garros and Nadal's current Davis Cup captain, says: "It's so tough because he's also a lefty but I would try to play the way I played before. "I would play to his backhand and wait for the short ball, but it's not easy because he has improved the backhand a lot." Costa is still playing on the ATP Champions Tour, which concludes with December's Masters Tennis in London, and was no stranger to a clay-court marathon himself. "Rafa never misses," he says. "He's hitting hard so he keeps you three metres behind the baseline. If he plays at the beginning at the same level as always then his opponents don't really feel like they want to keep playing for two hours like this." NADAL & BORG TITLE RUNS IN PARIS Nadal: 2008: Sets W-L 21-0 (100%) 2007: Sets W-L 21-1 (95.5%) 2006: Sets W-L 20-3 (87%) 2005: Sets W-L 21-3 (87.5%) Total Sets W-L 83-7 (92.2%) Borg: 1981: Sets W-L 21-2 (91.3%) 1980: Sets W-L 21-0 (100%) 1979: Sets W-L 21-3 (87.5%) 1978: Sets W-L 21-0 (100%) Total Sets W-L 84-5 (94.4%) * Source: ATPWorldTour.com Federer has suffered repeatedly at Nadal's hands and the 13-time Grand Slam champion's own incredible achievements are in danger of being overshadowed by the Spaniard. Nadal leads their head-to-head 13-7, and 9-2 on clay, and he has beaten the Swiss at Roland Garros for the last four years running, including the last three finals. Last year's 6-1 6-3 6-0 victory remains Nadal's most devastating display to date. "I know that clay's obviously a different animal," says Federer. "He plays extremely well on it and he crushed me in last year's French Open final. "For me it's about believing that I can win playing aggressive, not playing his style, and that's tough to get out of because he's such a great shot-maker, such great defence." Ferrero believes Federer has unintentionally spurred on Nadal in his domination of the French Open. "I think that taking the number one spot from Roger served as an extra motivation for him to win so many Roland Garros titles in a row - one led to the other," says Ferrero. "Roger had been number one for a long time and Rafa's improvement has to do to with the fact he needed to get better to be able to be number one." So, is it worth the others turning up on Sunday, or will we see a two-week coronation of Nadal? Federer admits Nadal "crushed" him in Paris last year "It will be tough to beat him but I don't think it's impossible," says Ferrero. "It's definitely a hard task but if he's not 100%, someone could beat him." Asked who could topple the champion, Costa says: "Federer, Djokovic, Fernando Verdasco maybe, David Ferrer. Murray is very motivated to play on clay but I think for the moment Rafa is still a bit better, but he is going to be very dangerous this year." Speaking after his defeat in last week's Madrid semi-final, in which Nadal saved three match points, Djokovic said: "Next time I'll probably take two racquets on the match point and try to hit them past him. I don't know what to do." But the man who craves the one title that would complete his Grand Slam set has not given up hope. "The belief is always there, I've played him so many times," insists Federer. "You've got to hope for one day when he's not that sharp, or maybe he's won that much that he'll question himself 'how many more times can I really do it?' "I'm not saying that's what happened to me but you sometimes start to wonder as a player when you dominate so much on a particular surface, like me on grass, you go out there and think 'how many more can I really do?' because the press keeps asking over and over. "He knows that guys are chasing him, even though he's dominating clay in an unbelievable way right now, and honestly what he's been able to achieve at his young age on clay is phenomenal. "But we're there, we're there to challenge him, and we'll wait and hopefully take the opportunity when it comes - especially me." " there is an interesting stats section on the big four in the link that i couldn't copy, showing the federer, as a %, has broken serve considerably fewer times than other members of the big four in 2009. thought that was interesting.