I'll make it simple. Which of these options resembles "Proof of Brain"?
A) 1000 people upvote a post and 1 person downvotes. Creator gets 99.9999% of his/her due rewards.
B) 1000 people upvote a post and 1 person downvotes. Creator gets zero rewards due to the one downvote having a greator voice than the 1000.