order captions by upvotes, and display # of upvotes, downvotes and total score on each caption, to reduce downvoting

People downvote everyone else so that their comment bubbles to the top. So, instead of ordering captions by their total score, instead they could be ordered by the number of upvotes they received. That way, the only way someone could influence the order that the captions are in would be to upvote captions.

Each caption would still display the number of upvotes, downvotes, and total score it's received, and if the total score is negative, then they can still be put into the 'bad comments' section (and of course people's overall reputation will still take downvotes into account) - so downvoting would still serve a purpose.

This way, captions that receive a lot of praise get to the top, and not just captions that get the least downvotes. As the image gets older and the number of votes the captions receive goes from 10s to 1000s, it seems people start mindlessly upvoting captions at the top of the list and downvoting captions that are at the bottom without reading them, so it's important to get the balance right at the start when an image is new and most of the captions only have a few votes each.