News for hackers. Stuff that matters.
Re:How I ended up with so much Hacker News karma by Timothee on Monday December 03, 2012 @09:49AM (#4865585)
I think it's something like the average of the last 50 to last 5 comments you've made. Maybe with some outliers removed as well.

The main point is that it's not instant (i.e. your last comments are not taken into account) and it uses only recent comments, rather than over the life of your account.

Re:How I ended up with so much Hacker News karma by MaysonL on Tuesday December 04, 2012 @06:24AM (#4870370)
And it ignores outliers [at least on the high side].