What Is a PSA 10 (Gem Mint) Grade?
PSA 10 is the highest grade issued by Professional Sports Authenticator, designating a card as Gem Mint. To qualify, the card must show 55/45 or better centering on the front, four sharp corners, clean edges with no visible whitening, and a surface free of print defects, scratches, or staining under standard lighting.
Detailed explanation
PSA 10 is the most-searched grade in trading cards because it is the price-multiplier tier — a card jumping from PSA 9 to PSA 10 can double or 10x in market value depending on the title. The grade is binary in commercial terms but technical in practice: PSA's published standard requires 55/45 centering on the front, 75/25 centering on the back, four pointed corners, edges without chipping or whitening, and a surface free of scratches, print lines, or staining.
Common misconception: PSA 10 does not mean perfect. A card with a 56/44 front-centering ratio can still receive a 10 if the other axes are flawless. Conversely, a card with picture-perfect centering can drop to PSA 9 because of a single corner ding or a print line visible only under angled light. Graders are human, and PSA's own population reports show a 30-50% Gem Mint rate even on modern, well-protected cards.
PSA 10 also differs from BGS 10 Pristine and CGC Pristine 10 — both of which require subgrade floors PSA does not enforce.
How AuraGrade measures it
AuraGrade lands within ±1 PSA tier of the eventual grade in approximately 70-85% of internal-test cases — if we predict PSA 9, you most often receive PSA 8, 9, or 10. The centering axis is deterministic pixel math (LAB-chroma ratio measurement); corner / edge / surface defects are identified by Claude Opus 4.7 Vision with bbox evidence; the final tier estimate combines both. Phone-camera scans are explicitly capped below Gem Mint regardless of detected defects, because hairline scratches and gloss loss are not visible in diffuse phone optics.
Worked example
A 2020 Pikachu Vmax with front centering 54/46, back centering 70/30, four sharp corners under 10x loupe, no edge whitening on the black border, and an undamaged holo surface meets the PSA 10 floor on every axis. Same card at 60/40 front centering triggers an automatic MC (miscut) qualifier and caps the grade at PSA 9.