Who will win in tonight's final and why?

Question

I am rooting Nadal and hoping him to lift the trophy but Fed is undoubtedly the KIng of the Grass for sure and he will not let Nadal to humiliate him again the way he (nadal) did at the recent French Open. So it would be a batlle royale between the two great players. KING OF THE GRASS vs KING OF THE CLAY. May the best man win and good luck to RAFA especially. How about DJOKO. HE's the KING OF WHAT???