Organizations were compared, yearly, based on how many of the top ten ranked fighters of the Heavyweight and Light Heavyweight divisions had the majority of their fighters in each organization.
This specific time frame was chosen due to Pride having had only one event in 1997 and only two events in 2007, neither years of which would provide an apples to apples comparison with other MMA organizations.
Rankings were from January of the respective years.
In the event a fighter had no majority number of fights in a single organization (i.e. 1 fight in Pride and 1 fight in the UFC for a single year), or didn't fight at all for the year in the division of which they were ranked, they were assigned no organization.
In the event of a tie between organizations for a single year, the tie breaker was whichever organization had the highest ranked fighter (see 2004 Light Heavyweight).
I was inspired to create this thread due to this ignorant post:
Pride Score
Light Heavyweight: 7
Heavyweight: 6
Total: 13
Pancrase Score
Light Heavyweight: 1
Heavyweight: 3
Total: 4
UFC Score
Light Heavyweight: 1
Heavyweight: 0
Total: 1
The UFC only ever won once (LHW 2004) and it was the result of a tie breaker.