One cannot compare the rhythm of a major clay match to a match on grass. On grass, many free points are given out, many streaks are in a match, when players go through the routine of serving. On grass, a handful of big points tell - on breakpoints or in a tiebreaker. Those few points decide on the result of a match. On clay against Nadal however, there are no big points, there is only the next point. You win points, you win some games, maybe a break, but it counts for nothing. The next point comes, and you have the same problem again. You get no free points, you have to play every point to the limit. Djoker is no big hitter, he never was. Only guys, who might have a chance in a set or so, are those big hitters, who can paint the lines for a while, like Soderling, Leconte, maybe Safin. If they can hold this level through 3 sets however, is a different matter. In my recollection, Soderling beat Nadal, when he was ill and overplayed.