What makes a topic appear in the "Top" filter?

Thanks for the guidance @Pad_Pors. I’d been trying to search for the old topics too (I know I’d seen some in the past).

I’ve been fiddling with all of the options I can find (searching “heat”) in the settings, but I can’t seem to find anything that helps push something onto the “top” post sooner, or perhaps just the minimum threshhold that it has to cross? Perhaps I’m just not finding the right options. (I’ll look through the code you sent me when I get home later to see if I can parse what the minimum threshold is)

In general, I’m a little puzzled about the heuristics still. In my current (still private) site, I have a topic that is listed in the “daily” top topics, but the weekly and monthly are still empty. If it’s the top of the day, and there are no higher topics in the week, shouldn’t it also be in the week?

See here:
http://162.243.159.122/
(The tiles at the top are supposed to fill in the rest with “Top” topics)

I’d like to believe that non of this will be an issue once I go live, but knowing that if we have a slow period, it’ll trip up the “top” categories and highlight just how slow makes me a little nervous.