>>12191432It's a board-wise incremented counter. I would say the odds should be the same regardless of thread OP/reply and regardless of time of day, or anything else.
Unless you're specifically trying to get a certain number. Then you can use scripts to get the most recent post IDs every second or so. Then you can have a captcha pre-filled and when the post rate is below a certain threshold and when a double is 1 post away, have the bot automatically post.
So if you assume there are people intentionally gaming the digits, then depending on whether those people are making more threads or more replies, those would be more frequently seen. But for someone who isn't gaming it, I think the odds should be the same.