A few weeks ago I watched some old matches of Thomas Muster including encounters against Sampras, Agassi, Courier and Bruguera and it is quite obvious that today's clay is far faster than it was then. Muster was able to hit five straight shots on the forehand wing, whereas currently he has to fire his forehand at least two or three times as fast to end the point. I just wonder whether his shots are more powerful now but looking at the shot and serve speeds it is probably not the reason. He uses the same strings as back then in 1992 or 1995, therefore it shouldn't be blamed on the technology of strings. So what's the main reason - the balls or changes in surface? Or maybe Muster's game is simply faster?