[nullc]

It's saying at the time I commented there were 35 posts in this thread with green names (36 now), while there were 0, 1, 1, and 1 in the other threads respectively.

If you want to go by the ratio of unique green names instead of posts this thread has 13 times more than those threads that had any at all.

[ddtaylor]

There does seem to be a lot of variance in that though. The top post on HN right now is from a green user name. Also the number of comments in the two threads is vastly different.