List of snooker ranking tournaments – Wikipedia

The first rankings were produced after the 1976 World Snooker Championship and were based on performances in the 1974, 1975 and 1976 World Championships. Because of this system, the 1974 World Snooker Championship is regarded as being the first ranking tournament.. The same system was used for a number of years but the rankings for the 1983/84 season included performances in two additional …

https://en.wikipedia.org/wiki/List_of_snooker_ranking_tournaments