Quoted from the page: fuzzing takes the number of votes and separately adds or subtracts a relatively small amount of votes from each of the numbers. The more votes on a post, the larger the range of the fuzzing. You pretty much don't see fuzzing when there are only a few votes, but on a highly votes post, the fuzzing can be much more noticeable. Example with 50/20 actual votes. On a page load, you may see 51/19. On another load, you may see 52/22. This also affects the displayed score, with the first load showing 32 and the second showing 30. This is easy to see for yourself. Find an old post (unlikely to be new votes) with a high score, look at the numbers, refresh the page, and look again.
The second thing is vote balancing. Balancing works by adding an opposing vote when a known cheater votes. So, if a cheater is trying to get a post to the front page and votes up a new post from 1/0 to 2/0, the system will add a downvote to balance, resulting in 2/1, consisting of 1 real vote (from the submitter) and 1 discarded vote. (Note that there are other triggers for vote balancing, though they are related to cheating prevention.)
Because of vote balancing, the percentage of upvotes is totally meaningless (will be closer to 50% than the actual percentage). However, because vote fuzzing is a small effect, the total score is generally correct, but is not exact (an actual score of 100 may show 102 or 99, but won't show 120).
TL:DR: Checks for known cheaters IP Address' and hides the true vote amount.
@OpToCo(View Post) Still has no use. This just confuses people. The whole point of the amount of votes being displayed is to show people the actual amount of votes.
@OpToCo(View Post) TPT already detects multiple account voting. It shows up on a moderator's screen when they open a save. :3 The user will then be banned, probably pemanently or for 2 weeks (first time).