[the 'stache]

I think they take the backs into consideration every time, at least with PSA and SGC. It's possible that something might slip by occasionally, but there is no doubt in my mind that the back condition factors into the final grade.

Here are three of my T206 cards. Look at the card, then look at the grades they received:



If the backs were not considered, these would be undergraded, imo (especially the Tannehill). But when you look at the backs, they are accurately graded because of tape stains, and a small amount of paper loss on the Rucker. I feel the back issues may have lowered the overall grade by a whole point.