In general we are pruning back to 2013, so 1100 days.
In some cases however, we are picking some of those threads to delete also as all the old sports threads and threads with zero replies.
Boards such as Local Meetups have no reason to save old topics. Same with Announcements.
We are leaving Overlooked Films alone as it's a film board.
CLARIFICATION: If the topic has not been posted in for 1100 days or ever, then it's deleted.