In search of a Digg rating algorithm

I’m not sure why, but all of a sudden I got interested in how Digg works. In particular how it decides which links get to be featured on the landing page. There’s quite a bit of thinking that goes behind that algorithm that drives it.

There doesn’t seem to be that much available out there. Here are a few interesting links that I found online:

• Scalable story promotion
• Writing a Digg-Style Popularity Algorithm
• Archive - the first day of Digg that’s in Archive.org has SQL in HTML comments. It’s obviously very simple and trivial, but does give a couple of hints about early inner-workings.I formatted it myself, the original source is all on one line.

select
  items.id as id,
  title,
  ctitle,
  url,
  bodytext,
  username,
  category_id,
  top_flag,
  category_autopost_threshold,
  dig_count,
  obscene_count,
  users.id as userid,
  approved,
  deleted,
  obscene_flag,
  sdelete_flag,
  catdaysback
from
  (items inner join users on userid = users.id)
where
  (approved = 1 and deleted = 0  and obscene_flag != 1) and
  (top_flag = 1 or (items.dig_count >= category_autopost_threshold)) and
  (sdelete_flag != 1)
order by date_promoted desc