The tall guy was Robin Soderling, and he actually won the match in 3 set but his ball was called out on match point, it was not. And ok I agree with you that Sampras is a better grass court player than Nadal, and in his prime I would have my money on Sampras too, but look the grass is a lot slower than it used to be, John McEnroe even suggested it was slower than the Decoturf at the US Open, but right not. Remember Sampras' trouble returning Fed's serve, he would also have a really hard time returning on grass, so he would get almost no looks at a break and all Nadal would have to do is get Sampras' serve back then he could undo him from the baseline, and when Sampras served and volleyed he would def win a few points but eventually Nadal would put a couple passes together and get his breaks, but don't forget Nadal's got no idols, hes not afraid to pound a legend, he did beat Pat Cash when he was 14 if Im not mistaken, so if it got a little rough for Sampras it could be a long day and a taste of reality.