Then perhaps a comment with 20 up, 5 down, and 500 neutral would rank lower than a comment with 20 up, 5 down, and 0 neutral. The idea being that, all things being equal for two comments, the one with more indifferent voters is considered less valuable, and is thus ranked lower. Maybe a neutral vote simply works by increasing n when judging the size-weighted score that HN uses to calculate rankings now.
I'm sure there are flaws in this line of reasoning..perhaps someone would be so kind as to point them out?