The scoring system was changed for session five.  A ranking is awarded after 8 games have been played.  The average is based on all games played. 

Session 33 included the option for players to 'freeze' their scores once ranked. Once frozen the average will not change, but first place finishes were still tracked and shown after the players name in blue like this: [33]

All league game scores for session five onwards are calculated as follows:

1st - 256 points, 2nd - 128 points, 3rd - 64 points, 4th - 32 points, 5th - 16 points,
6th - 8 points, 7th - 4 points, 8th - 2 points, 9th - 1 point, 10th - no points.

Check out the current scores here.