Not simple. Rewards are based on a factor called reward shares. reward shares are proportional to Steem Power. The rewards on a post used to be determined by R^2. Now it's just R. The effect of R^2 made it so that it was much more valuable to have many people agreeing on a post and little effect even if just 1 whale liked it. Now, who else values it doesn't matter. The only thing that matters is how big of a vote it gets.

If I ran a bidbot before and voted on a post no one else liked it would pay shit. Now if I put money into a bit bot it'll pay. that's because of the shift of exponential rewards to linear rewards that happened in HF19.

that's the quick and dirty version.