Djokovic since 2007. Puerta was good in 2005. Olderer had one of the best seasons on clay in 2006.
I never said Olderer was a bad player, btw. I said he lacked a true rival off clay until late 2007 (not surprisingly he became monofed and then Olderer according to his fans).
I never said Nadal was a bad player, but he has lacked a true rival on clay for his entire career. Djokovic? Please! 12-2 is similar to the Fed-Roddick H2H on HC. And Roddick has won more on HC than Djokovic on clay. So your opinion of Djokovic as a clay rival for Nadal should no more than equal your opinion of Roddick as a HC rival for Fed.