Comment by IgorPartola

Why not push really long threads to the bottom? People will find the long discussions by scrolling to them. Indeed, they will know that they are there, just like now we know that the long discussions are at the top. The effect though is that now readers have to get past other discussions first. Basically, the order should be short-good, long-good, all-crap.

Also, while this may be a problem here, HN still has the best comment sorting system I've seen (but not measured). Comments have time to stay at the top and simmer down and if they are good they gain enough momentum. The only time this seems to be come a problem is when you get to a really popular thread after hours/days of discussion. Then you cannot get a word in edgewise.

An alternative solution could be that for every comment you make, you give up a bit of karma and you gain it back through comment upvotes (but not article postings). That way people will watch what they say. This may give some positive feedback to posters that harvest huge amounts of karma, but it will also prevent bad comments. On top of that, you could make your post stick up top longer by paying a blood price: for every 50 points of karma you get another minute guaranteed at the top of your discussion thread, or some such. Or just free market FTW: the person that bids the highest amount wins the top spot for that many minutes.