[sarabande]

One way to calculate this would be to use this controversy formula (https://math.stackexchange.com/a/318510/10887) on all comments of a user whose total karma exceeds a certain threshold, say 1000, and then add up those controversy scores.

The problems is that the HackerNews API (https://github.com/HackerNews/API) only provides a total score for a comment, instead of up and down votes, so you'd have to modify your controversy formula to use an appropriate measure of dispersion instead (https://en.wikipedia.org/wiki/Statistical_dispersion).

I'm not a statistician myself, so I can't help further.