Card grading question

I found a bunch of old base set japanese basic energy cards that have perfect corners, edges, and centering, but the surface has light scratches only visible when you hold it under a light and move it around. How much would that affect the overall grade of the card? Could it still come back a 10? or would it knock it down to a 9? or a 8 even?

www.elitefourum.com/t/the-giant-professional-grading-thread/30930/1