I told him about the rank thing, when I said it, I didn't mean that the rank goes down by 1, look at this "graph":
Upvote: +r
Downvote: -r
Time: -r
More r = meme closer to the front page, example:
Meme 1 (10r)
Meme 2 (8r)
If a user downvoted meme 1, it's r would still be higher than meme 2's r and it would therefore be higher on the front page, if 3 people downvote meme 1, it would look like this:
Meme 2 (8r)
Meme 1 (7r)