That is a 14 year old HN post linking to a dead article, the comments on which say things like > This is not the 'hacker news' ranking algorithm, this is the

That is a 14 year old HN post linking to a dead article, the comments on which say things like > This is not the 'hacker news' ranking algorithm, this is the ranking algorithm distributed with 'ARC', which is the basis for the HN algorithm, but definitely not equal to it. The biggest missing ingredients are flagged posts dropping off quicker and posts that contain no URL dropping off quicker but there are quite a few other subtle tweaks. Not really "public".