I may be totally wrong here, and I'm curious to hear directly from CSG too, but it appears their grading scale is basically the same as BGS. And my understanding is, the overall grade can only be .5 higher than the lowest subgrade on the card. I had a terribly off-center 1986 Fleer Barkley, but the card was fairly NM overall. So I assume the centering was a 6, meaning the highest overall grade possible would be a 6.5. (Assuming the centering is the lowest subgrade for the card.) I've attached some images of the card for comparison.