there's always going to be a set of criteria where you don't get a fair chance with a commenting system, imo.
chronologically, late posters get ignored because there's lots more content for people to get to. earliest posts tend to have the most attention.
reverse chronologically, early posters eventually get ignored and people who duplicate/repost early content tend to get rewarded for doing so. conversations tend to be more circular and rehashing happens often.
weighted, late posters get ignored because the quality posts rise to the top, and people tend to not read down far enough to hit the new posts. quality posts get more attention and replies, further pushing down later posts.
LESSON FOR HN POSTING: early bird gets the worm.