I have never been a judge at any fish show. I am always an entrant. I do know it's all about conformation, general healthy(no split fins, ect) and usually the mood of the judges. There is some politics involved I'm sure. Unfortunate, but I'm afraid it's true. Many shows you can only show mature, full grown fish unless it is a catagory of family(motjer, father and fry) or juveniles specifically. Many judges are traditionallists that frown on anything other than whether the fish conforms to a traditional standard. In the case of bettas the only colors some judges will accept are reds, blues, or combinations or varieties thereof. They do seem to be loosening up some since many of the old timers are not judging and new blood has taken their places.