[stevenh]

Suppose there's a comment with 12 upvotes and 207 downvotes. Now suppose you're reddit and you want to make this comment seem more popular than it actually is.

You could slowly remove the downvotes, but attentive people refreshing the page will see the number shrinking and become suspicious, because real users never suddenly do a mass retraction of their votes.

You could slowly add a bunch of upvotes, but then people will wonder why this comment with a consistent 12/207 popularity ratio for the past hour suddenly overcame it and became the most popular comment in the thread. People will suspect a coordinated raid took place.

Both approaches raise too much suspicion. The safest approach is to turn off the ability to view the separate upvote/downvote values altogether and use a simple easing function to artificially increase the comment's total score over time. When no one can see the upvote/downvote ratio or the volume of vote activity over time, they lose the ability to judge whether manipulation is taking place.

You need an excuse for the change, so don't forget to also come up with a spurious narrative about how it was supposedly done to fight bots.

[joshuamorton]

Except that vote fuzzing was always a thing, so when you'd see 1000 upvotes and 100 downvotes, that could be off by an enormous amount (I think a reddit admin said by a factor of 5x or 10x in extreme cases, ie. frontpage posts).