The first world rankings were introduced after the 1976* world
championship based on performances in that event only over the previous three
years. The main purpose was to determine the seedings for the next year’s
championship.
As more ranking events were introduced in the mid 1980s, the
rankings were based on the last two season’s performance in all ranking events.
Most of the events earned the same points but in order to reflect
their relative importance, the UK Championship and, to a greater extent, the
world championship, carried higher points tariffs than the others.
Although the actual points awarded has changed over the years, the
system itself remained largely the same up to the end of the 2009/10
season. From the onwards a two year rolling ranking system has been
used whereby points scored for events more than 24 months previously
are dropped on an ongoing basis. For seeding purposes there are cut-off
points in October, December, February and at the end of the season.
The full ranking list published after the world
championship each season includes all players who are members of the World
Snooker Association, even those who are retired, but I have only included the
top 32 for each season in these historic records.
* There was an Order of Merit published after the 1975 world
championship on which seedings were based for 1976. As this was
produced using identical criteria to the first official ranking list I
have included it here.
