top-bottom centering on 1954 Topps
 

Apologies if this has been asked elsewhere, but how do the grading companies measure the top-bottom centering on a 1954 Topps card given that there isn't supposed to be a top border. That is, since 100% of the top border + bottom border is, by design, at the bottom, what ratio are they comparing? And is it the same for PSA as for SGC?

I think they compare the three visible borders and how close the printing is to the top, but I have no idea other than experience collecting the set (3x and counting).

I agree; the bottom border should be the same as the left and right borders on a perfectly centered 1954 Topps.

Okay. Thank you.

Trimmers
 

Wondering if card doctors target this year for trimming :(, especially with so many key rookies in the set