I am not terribly experienced at these contests having never won one, or even placed. I find them entertaining to enter from time to time and am fortunate I dont rely on them for my income.
I suspect I'm not the first to address this. I did not do a search for similar topics, I must confess. Contests where one can see others entries seem to me to foster "oh if I just change this, mine will be an improvement over this other entry" or other divining after seeing other contestants improved solutions: "That's what they want" That seems ok in a sense.
I like the idea and cleanliness of blind contests as it pushes people to find their own paths to solutions. One will get a greater diversity of ideas, -a plus for the client, and it will allow designers to work from their own scope of knowledge.
Another thing I think is not particularly effective is permitting clients to submit vague briefs. A good sentence is half a good thought, as my mum used to say. Briefs should be packed with information. Likes, dislikes, color options, size, font possibilities as well as something more than "not like Starbucks" or "like Kentucky Fried Chicken".
Lastly, just two other things. If the contest is not blind, when entries are eliminated, it would be helpful to see them. As it aids in knowing what the client doesn't want. A particularly necessary facet with clients that are not communicative or have a difficult time conveying what they want. Hand in had with this. When a blind contest is finished, It would be great if the entries were uncovered so one could see people's efforts and solutions. I'm not sure, I think now one can see the winning entry, but not the others?
I apologize if I'm banging on a dead horse and all this has been addressed.
. Also the entries are made visible at the end of a blind contest 
. Further, the briefing of the contests are visually supported by a slider system. Due to this system the contest holder can give a direction to what they like to see in a design. I use it all the time. For me the slider system is very helpfull.
