I wondered about this, but sometimes people say it cause the previous post they see is 999 so they post it, sometimes you get lucky as heck haha. I doubt they'd screw with the admin tools just to do it.
On big boards there's so many posts per hour that it's impossible to really predict this way, it's very much luck.
I remember people used to run scripts to be sure to get the big gets (6+ last digits identical) but I suppose such methods don't work anymore with captcha and other anti spam measures.
