When Roger and Rafa met on grass and clay

Fifteen years after Rafael Nadal and Roger Federer played on a half-clay, half-grass tennis court...do you like it, loathe it, or love it? Absence makes the heart grow fonder, but this was such a unique setting—for an exhibition, if that even needs to be said—that your opinion in 2007 likely still holds true today.

Dubbed "The Battle of the Surfaces," Federer and Nadal traveled to Rafa's homeland of Mallorca, Spain for the quirky contest that would theoretically determine the best player in the world. (As you might expect, Mallorca has many clay courts, but it has also hosted tour-level events on grass.)

Federer entered The Battle of the Surfaces having won the previous four Wimbledons (he'd win another a few months later) and his last 48 grass-court matches. Not to be outdone, Nadal had won the first two French Opens he'd enter (he'd also win the next two) and his previous 72 clay-court contests.

So how did it turn out? At the end of the $1.6 million spectacle, Nadal won by a blade-of-grass, or granule-of-clay, margin, 7-5, 4-6, 7-6 (10).

But let's not forget hard courts. Ten years ago in Madrid, the pros slid around on the fast surf...no, wait, they slid onblue clay. The winner of that one-time only blue-clay tournament? Federer.

Which surface was weirder: the clay-grass combo from 15 years ago, or the blue clay from 10 years ago?