Naaah, I've been there for two Cannabis Cups and while it's fun, the 'judges' are just guys & gals like you & me. No special credentials other than buying a judges pass and going from shop to shop stoned out of your gourd. I don't know about you, but after I've smoked 2-4 different varieties, I can't tell one from the other. How they possibly could 'judge' the finer qualities of many strains is beyond me. One of the judges I knew was tripping on mushrooms most of the time.
It's more of a popularity contest.