Ask HN: How are comments ordered?

Let me preface this by saying that I am aware the submission ranking algorithm is something of a trade secret and I trust this thread about comment ranking will be removed as appropriate if inappropriate. Likewise if there is already a topic on this with the goods then please link it, and feel free to insult my Google Fu while you're about it. Here's what I have so far: 1.) Karma is used to rank comments. 2.) New comments have only 1 initial karma point, yet enter the thread quite high (if not at the top?) then, assuming they are insufficiently upvoted, sink. 3.) I don't know how important to a comment's ranking its descendants are, nor the extent to which a reply's karma affects its ancestors. 4.) The 1 initial karma does not contribute to the poster's total, so seems to me like a way to +1 some part of the ancestors' ranking score calculation to represent that it has inspired one new comment of discussion. 5.) I have no idea what happens in a "tie-break" situation. This thread is motivated almost entirely by a comment I made today which has been upvoted a lot more than I am used to being upvoted. It is a first reply to another comment and at the time I replied, that comment was near the bottom of the thread. I chose to reply to it because the poster was making enough of the same point I wanted to make that I could just say "Indeed" and then post my own comment without having to establish context. Given that the parent is now the second highest ranked un-nested comment in the thread, and I've got a lot more karma than I'm used to, I rather wonder on whose coattails who is riding, or if the two of us are sailing some kind of slowish coattail catamaran.