we who watch tennis more than 15 years remember how fast was surface on Australian Open in 90s and early 00s
for example look highlights of 2000 finals between Andre Agassi and Evgeny Kafelnikov
Average exchange between two players was 5-6 shots .
You can say by looking the ball speed that surface 12 years a go was like double faster than today.
Um, the surface doesn't look all that much faster to me. I've seen other places describe Kafelnikov as an aggressive baseliner so I doubt he would have the defense of Novak or Rafa.
For all the talk about surface changes few people don't seem to talk about just how much athletic the players have gotten in the past 20 years.