It is another statistics that says to us that in case of Nole the difference in results between his best and worst surface is the closest among the tennis greats. If he wins the DCGS on Sunday there is no doubt in my mind he is the most versatile tennis player of modern tennis and probably of all time. People claim that clay is his worst surface and it is correct in my view. But... 10 masters titles on his worst surface, at least two titles at each masters event on clay, 11 straight quarterfinals at clay major, etc. The only thing missing is second RG title.