[7] After World War II, with an increasing number of prominent professional players, there were occasionally tournament series with point systems which created official rankings for the complete field of pros.
The last World Championship two-man tour was held in 1963, featuring a final set of matches of Ken Rosewall against Rod Laver.
(Professional Players Association of Tennis) linked by a points system won by Bobby Riggs, which he relied upon as evidence of his mastery of the entire pro field.
[36] In 1959, Jack Kramer established a series of 15 tournaments in Australia, North America, and Europe linked by a points system which provided a full field ranking of all the contract professionals, plus a substantial money prize for the top finisher, with Lew Hoad emerging as world No.
[39][40] In 1960, Kramer again established a tournament series with a points system, but both Gonzales and Hoad withdrew from the field and the final results are unknown.
[42] Beginning in 1970, the ILTF authorized Kramer to arrange a year-end championship in which the pros with the highest tournament series points competed for the title of Grand Prix champion.