There are factors beyond naive weightings, as well. I remember reading somewhere that if a thread becomes too heated or turns into a flamewar, the mods have the ability to suppress it in the rankings artificially to let it cool off. That functionality makes sense, but wouldn't be easily identified in a third-party tracker.
A lot of comments here seem to be assigning moderation as bias.
A lot of comments here seem to be assigning moderation as bias.