Originally Posted by Vrad
Hmmm...Grass below clay?
Before the Fedal era, and especially during the Sampras/Agassi era, clay was an afterthought. It was Nadal's ability to break out of the clay court specialist mold, and Federer's ability to succeed on clay that has raised clay's profile, at least since the 90s (when I started following tennis).
It has to do with how many tournaments are on the surfaces.
Hard - 50%
Clay - 40%
Grass - 10%
It's easier to dominate grass because it's a super specialist surface. Hardest to dominate hardcourts due to the near ubiquity of the events on tour, so Federer's achievements there are almost equivalent to me.