Judging criteria has much to do with the quality of the character. For example, if somebody RPed a wrestler named Problem Child, you might want to give them some extra points for being unique. As far as how roleplays are graded, I'd say innovation is key. Like, for example, if you had one character named Problem Child, and he's facing someone named, I dunno, Jared Wells let's say...and Wells photoshopped a picture of a chick, but Problem Child re-photoshopped her to give her a black eye, that would probably be enough to get Problem Child the win. I'm just giving examples here, this could go for anybody.
But generally speaking, here's what we look for in a good RP:
-Character comes out to themes by the Deftones
-Character is involved in RPs where he digs up former title belts out of the sand
-Characters named Problem Child
-Characters with mullets
Hope this helps,