Originally Posted by Mustard
If we add the 8 professional slams that Laver won between 1964 and 1967 to the 6 he won as an amateur and the 5 he won in the open era, then Laver has 19 slams. Laver also achieved the professional grand slam in 1967.
To be honest, I'm surprised that the professional slams are not counted towards a player's slam total when a player turned professional before the start of the open era.
Many tennis historian do count it. Rosewall would be the leader with 23.