The only way you can find out how those bidders bid is that if you can spot a pattern of a specific account and which are the frequent few gets the winning bit.
If it is still too random, them probably we just have a lot of gamblers there, or, if these accounts are related as in (always following each other, or always that stronger account vote for the weaker account) in order to find out is there a syndicate running behind or not; if you get what I mean.
upvoted
ps: Best next time don't post your almost expiring post into the steem engine promotion site, none of us can really be able to help you much on that.