Centering standards (PSA vs. Beckett)

[darwinbulldog]

Excuse the off-topic card, but it's the one that got me wondering, what exactly are the cutoffs for Beckett to give a 9 vs. 9.5 vs. 10 for the centering subgrade?

With PSA it's...clearly(?) posted on their website:

"The image must be centered on the card within a tolerance not to exceed approximately 55/45 to 60/40 percent on the front and 75/25 percent on the reverse."

And that's for a PSA 10! Which apparently only needs to be approximately as good as 60/40 and 75/25. So 61/39 on the front and 75/25 on the back should be fine according to their published standards. This seems like a big discrepancy from Beckett. I measured the borders on this card from eBay last night to the exact pixel, and the worst measurement (top/bottom or left/right) is 54/46, a ratio so good that it doesn't even fall within the range PSA provides for a 10, but Beckett says the centering is a 9.

Are they really that much stricter than PSA? Or is PSA lying about how they grade centering (to entice more regrades and crossover submissions perhaps)? Or did the Beckett grader just make a mistake in measuring this one card?