I have no issue with the way the contest was run, but keep in mind that in general posts at the beginning of a thread will get more votes/likes than posts near the end of a thread, simply due to the number of people that see it (i.e. the first post in a thread is seen by everyone that enters the thread and the last post would only be seen by a few). In other words, a post in the beginning might have been liked by 5 of the 200 people that read it, while a post near the end might have been liked by 3 of the 10 people that read it. Based on that, initial entries had a much greater likelihood of winning (mathematically speaking), but as you said, each contest is different.