@luis_in_brief @jessamyn I remember @joeyh published a blog post once that was sort of a Jane's Guide to Thread Structures. You could see from screenshots of the thread indicators whether something was a dogpile (lots of people responding to one post midway through a thread, but no further engagement after that), or "get a room" (two people replying back-and-forth, for screenfuls), or any number of other common patterns.
Of course he also set up the mailman-haters list, which I recommended use the controversial "moderate unsubscription" feature, so nobody could leave...