The reality is that the strongest predictor of payout is the name of the author. There are very many bots operating on this platform, and the most common of these either vote for pre-defined author lists or are dumb vote-followers and vote for posts once they see that some other account has voted for them.

I've created a more advanced bot that is neither of these. My bot learns what kinds of posts make big rewards, and then votes for them - and the biggest thing it's learned so far is that the easiest way to predict a post's payout is to look at the author. It's not a very good system yet, but that's the state of things.