People can still vote down a comment even after it's hit the -4 floor. It's still counting against your Karma even after hitting that floor.

Ah! Thanks.

I didnt know that -4 was the lower display....

It's supposed to discourage people from piling on. Doesn't really work though (as you've seen).

I guess it deploys a sophisticated, proprietary, patent-pending algo involving weighted averages, uni-directional vectors and other related mumbo-jumbo. :-)))

[A method and a process to calculate the Karma score of members]

On a serious note, I joined here only early this month and have wondered about this once or twice myself. However, I post here mainly to share what (I think) I know and because I generally like this community; I'm sure there's a lot to learn here.

In the end, I reckon if I keep doing my thing, Karma will (eventually) sort itself out. ;-)

In a related question, what level of karma is necessary to be able to downvote? I have a lowly 72 points, and that's not enough. What is?

I just got it at 500. I'd reached the downvoting threshold once or twice before, but then lost the privilege when the threshold was raised.

It was increased recently to 500, I believe.

I believe it's 200.

It went up to 500 not so long ago.

I believe it changes over time?

I used to be able to downvote as I hit the 200 mark, but now I am well over 300 and can't downvote.. Perhaps it is related to the time spent on HN?

Nope. I'm nearly at 400 and I can't find a downvote button anywhere.

I would be interested in learning more about the decisions behind the HN comment system. It works well.

why worry about karma if your comment is honest, useful and decent enough