https://news.ycombinator.com/item?id=46829029#46875831
It's essentially comment karma (total up votes)/words ratio. I do think that I have a less karma ratio but that's probably because I write a lot of words which sometimes not even land a single +1 but I don't think that I would be a plain spammer. If you want I can try to find the highest ratios if that's what you like but I feel like that might have the issue where people with less words but with very high upvotes might have the likelihood of being spam/scam too when you think about it? Essentially, I feel like I can provide the query & then you can run it/modify it on the things that you might be interested to find.
Hope it helps!