[wlesieutre]

From the FAQ:

How are stories ranked?

The basic algorithm divides points by a power of the time since a story was submitted. Comments in threads are ranked the same way.

Other factors affecting rank include user flags, anti-abuse software, software which demotes overheated discussions, account or site weighting, and moderator action.

[andrewflnr]

Indeed, the "overheated discussions" factor probably downgrades (ed: rather, tends to downgrade) heavily-commented stories, not the other way around. I for one tend to regard a high upvote/comment ratio as a positive sign about a story.

[dspillett]

Measures of “overheated discussion” probably can't distinguish easily between matters that are purely divisive and those that are genuinely complex/interesting/ground-breaking/surprising/etc (so deserving of that much of people's time). Whether punishing based on this measure for this reason is beneficial overall or not is a divisive discussion in its own right!

[andrewflnr]

Not easily, no, but I think a very fast reply frequency, especially between lots of pairs of two people, is more indicative of heat than light. :) (who knows, maybe the algorithm will think that about this reply) Genuinely interesting topics probably require more time to write worthwhile comments on, and draw in more people.

(To be clear, I'm not implying nor do I think that HN uses raw comment-count as a signal of overheating, just expressing my surprise at the previous poster's surprise at seeing high-ranked stories with few comments, since the correlation should run the other way if at all.)