Does a 10 mean the same thing at PSA, BGS, and CGC?
Summary
No. All three top out at 10, but each company writes its own standard. CGC splits its 10 into Pristine 10 and Gem Mint 10, and Beckett also calls its top grade Pristine 10 and gives a special black label to cards with four 10 subgrades.
CGC's two tens
A CGC Pristine 10 is flawless under 10x magnification with 50/50 centering. A card that misses any one Pristine requirement becomes a Gem Mint 10, which allows centering of about 55/45 on the front and 75/25 on the back. Mint 9 widens that to 60/40 on the front and 90/10 on the back. CGC also notes that its old "CGC Trading Cards Gem Mint 9.5" corresponds to today's "CGC Cards Gem Mint 10."
Beckett's half points and subgrades
Beckett Grading Services issues final grades in half-point steps (10, 9.5, 9, 8.5 and so on) after judging centering, corners, edges, and surface separately. A card that earns a 10 in all four subgrades gets a black label, which Beckett introduced in 2014 for modern cards; it does not apply to BVG, Beckett's line for cards from 1980 and earlier.
PSA's ten-point scale
PSA grades only cards it has judged authentic, on a scale of 1 to 10, and prints the grade and certification number on the label of a sealed case. So a PSA 10, a CGC Pristine 10, and a BGS Pristine 10 share a number and nothing more; each is a verdict under a different company's rules.
Sources
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