I have routinely failed to understand the selection criteria for OGS. In any given year I'll see people awarded an OGS who really had strong applications (publications, meeting invitations etc...) but invariably there will be somebody in an upper year of their PhD program with what any logical person would assume is a much less competitive application (no publications, poor letters) and yet they'll be awarded a scholarship. All I can say to those of you who were unsuccessful is to keep trying. It took two rounds for me to be awarded a scholarship, it's hard I know, but try to stay positive and keep applying!
~Stargazer767