I would like to predict the first and the second half of the season separately from each other.
For the first half: In the administration area, go to "Match days" and delete all the matchdays of the second half of the season. You also have to delete all bonus questions as they are with respect to the whole season. Hence you also have to delete the matchday "Bonus".
The prediction game is set such as only the first half is being predicted. The same process can be applied if you want to predict only the playoffs of a tournament.
For the second half: As soon as the first half is over and the winner has celebrated properly, the administrator should go to "Restart" and restart the prediction community with the corresponding competition. All the points and matches will be deleted and the upcoming matchdays added to the calendar. The prediction game for the second half can now start.