Yep, the rank is based on your points (D). To me more accurate it is based on your relative position in the Hall of Fame:
The first 5 percent are ranked as "Diplomat".
Top 10 percent as "Mastermind".
Top 20 percent as "Pro".
Top 50 percent as "Experienced".
Top 90 percent as "Member".
Top 100 percent as "Casual player".
The rest, so the players with currently less than 100
, that are not listed in the HoF, are ranked as "Political puppets".