I put this in another thread also and copied it here.
Agreed Rosewall was a superb clay court player but not superior to Borg imo. Borg at his best on clay is arguably superior to Nadal. For example he won the 1978 French with the loss of only 32 games. He destroyed Vilas in the final with a loss of only five game.
Actually Rod Laver has a good case to be ranked over Rosewall as a clay court player. I believe he has beaten Rosewall as many times as Rosewall has beaten him on clay and perhaps more. Laver won the French twice and the Italian twice. He won the French and Italian during the Open era. Laver also won the powerful French Pro with all the great players participating like Rosewall, Gonzalez, Gimeno, Newcombe, Stolle, Roche, Emerson, Drysdale and Anderson among others.
If I counted correctly Laver won more clay court tournaments than Rosewall. He won the equivalent number of French titles. He won the Italian twice which was regarded as the fifth most important tournament of the year next to the majors. He won the 1968 French Pro which had arguably the most powerful field of all time French Pro tournaments because all the top pros could now play.
Rosewall won the French twice and the French Pro on clay four times.
I believe Laver has a very good case to be ranked the third best clay court player of all time.
You count the Italian Open on par with any of Rosewall's clay majors?
Laver being the superior player could have the superior level on all surfaces when playing well. But I'm still not sure he achieved as much as Rosewall on the surface.
What are their tournament totals in your opinion (on clay)?
Laver's prime years and time in the amateurs occurred during periods when there were more tournaments being played IIRC. Rosewall in the early 60's played few tournaments. That could explain his higher total of clay tournaments.
Their h2h would be interesting to look at if you have any details on that.
My conclusion is that Laver is perhaps a superior clay court player to Rosewall. Could change later.
Now when I say superior clay court player I mean for LEVEL OF PLAY. I think the information I have indicates Laver was superior to Rosewall on clay. Think about it. Laver won more clay court tournaments. Edge to Laver. In the only Pro Major on clay that both entered Laver won it over Newcombe in the final in the strongest field in the history of the French Pro in 1968. Very big in Laver's favor. They met in two French Open finals. Rosewall won the first in four sets and Laver won the next in straights. Equal in matches won versus each other but Laver leads in sets won 4 to 3. Tiniest of edge to Laver. Laver also probably leads the head to head on clay court tournaments. Edge to Laver.
Now Rosewall won four French Pros on clay while Laver won none. That's clearly an edge to Rosewall. Here’s the problem, Laver NEVER PLAYED A FRENCH PRO ON CLAY until 1968! Laver could not possibly catch Rosewall who played many French Pros (five) on clay before Laver even turned Pro. Rosewall won four of five only losing in crushing fashion to Tony Trabert in three straight sets winning only four games in three sets in 1959. Trabert won it that year over Sedgman.
Now the big question is who had the superior record on clay?
Rosewall, with his extra French Pros may have the superior record but that’s mainly due to his extra chances to win on clay in the French Pro. That's like why Roy Emerson won more classic majors than Pancho Gonzalez? Answer is because Gonzalez couldn't play the majors for years. However even Rosewall's superior record on clay is very debatable because we are looking at the whole of the clay court career. Ask yourself this, how would Laver have done from 1963 to 1967 if the French Pro was on clay without Rosewall around? Is it reasonable to believe he would have won two, three or four at his peak? I think so. Let’s say he won merely two French Pros on clay. That would give him three French Pro titles, two Italians titles, two French championships, more tournaments won on clay than Rosewall and a probable better head to head on clay matches. That’s more than enough for me to believe his record
and his level of play was superior on clay to Rosewall.