For the calculation to take effect at the end of the season, someone in the game needs to have 70% or more of the total points calculated. So for games that are pretty close, it wont matter if you try to use the system etc, you need (IMHO) to have a pretty big advantage for the auto-end to kick in.
All other ongoing laddergames will be transfered to the next season.
Or am I missing something here?