You CAN say the greatest of all time SO FAR. Of course that is still debatable since folks have different ideas of GREATEST. Who is the GREATEST hockey player of all time? SO FAR? I say Bobby Orr but there were others like Gordie Howe back in the day. Or the greatest football player or baseball player of all time? SO FAR? Unless we can fortune tell mind read and future tell you will never know RIGHT NOW who is out there who will be much greater much better. Everything is temporary. Pete Sampras was "the greatest of all time tennis player". Then Roger Federer showed up. That's the way life goes. The potential for BETTER is always out there. That's a gpod thing isn't it?