Nick Bollettieri: Paris clay gives Federer chance of toppling Nadal

It is the rivalry that we've dreamed about for years. And after three head-to-head instalments already in 2006, and a fourth seeded to happen in the final of the French Open, Roger Federer v Rafael Nadal is truly developing into a classic series.

Federer is, without doubt, the best player in the world, all round, and in many people's eyes, already has a strong claim to be the most naturally gifted player who's ever played the game. I've already subscribed to that camp.

But Nadal, with his scorching current record run on clay, and his power, his energy, and his dazzling strokes under pressure, has all the ingredients to usurp the Swiss master, if he stays fit and hungry.

On head-to-head statistics, Nadal also has an advantage over Federer, winning five of their six meetings, including all three this year as well as last year's French Open semi.

With all that in mind, my expectation for this year's event at Roland Garros may sound a little strange. I expect Nadal to make the final whereas I expect Federer could stutter in the French capital - and I was honestly of that mind even before his less than perfect first-round win over the Argentine qualifier, Diego Hartfield, yesterday afternoon.

Yet I believe that if the final does pan out as the seedings dictate that it should, with Nadal against Federer, then I take Federer to win it. Why? First, because with every match on the surface, he's getting more acclimatised to the clay. You can see in his game that gradually the instinctiveness with which he plays on other surfaces - exemplified by his near perfection on grass - is coming into his clay-court game.

Not so long ago, you could actually see him thinking out shots on clay. For my money, he is thinking less and running on instinct more, and that's a good sign.

Second, the clay in Paris is better suited to his game than the heavier clay you find in Italy and Hamburg. If he is going to upset Nadal on clay, Paris is the place for it.

Third, the pressure is all on Nadal's 20-year-old shoulders. Sure, they're some shoulders, capable of stinging shots and carrying great hopes, but anything less than the title and he's fallen short of what's expected. He is the man that everyone wants to topple this fortnight, including Federer. That makes mental toughness every bit as important as physical skill and there are few as capable of serene focus as Federer.

My fourth reason for backing Federer, if he gets as far as the final, owes a little to faith in destiny. Until and unless Federer wins the French Open to complete his Grand Slam set then the minority of people who do not already feel him to be the very best in history will always have that gap in the trophy cabinet to point at.

Federer knows that too, and believe me, this is the one title now that he would delight in capturing. A danger-laden draw awaits him, but he has the desire and the ability to get through.