For me this occurs with my comments that are overly anti US and snarky ("Omg bad healthcare, so third world, bla bla"), or when I get too political ("Yeah but Hillary was not really an alternative, she's an arms dealer..."), often on (soon to be) flagged threads. Yeah I listen to no Agenda from time to time, downvote me ;)

My posts mentioning Ayn Rand are also heavily fluctuating, sometimes tipping up, sometimes tipping down.

I always wonder: What are the most up AND down voted comments? I mean you can score a 1 with 0 votes, or with 100 up and 100 down (I guess, not sure if that is the formula). The second remark is of a different nature but will not give different karma.

FWIW, In all cases I agreed with Dang. I get carried away "twitter style" sometimes. Dang guards the quality (no short snide flaming remarks) and focus (we talk tech here people) of HN threads well.

For comments I find that a polarizing comment may yield karma but tip one way or the other (you know, it will polarize), but finding a smart middle ground though, is quite a sure way to score karma.

Yeah I wish we got to see both instead of just the current balance. You'll notice your comments do better at first and then drop later, I suspect because some interests have google alerts or the like set up. I started getting muted a lot less often when I started keeping a list of "sacred cows" that will quickly get you flagged for a divergent opinion.