The short answer: a PSA 10 needs roughly 55/45 or better on the front and 75/25 or better on the back. An Ace Grading 10 needs better than 60/40 on both. So Ace is a little kinder on the front and a lot stricter on the back. If you want to know where your own card sits, our free card centering tool measures both sides from a photo and shows the grade each company's rules allow.
Centering for a 10 at a glance
These are the limits each company publishes for its top grade and the one below it, as we read them in September 2026. 55/45 means the wider border can be at most 55% of the two opposite borders added together.
| Grader | 10 front | 10 back | 9 front | 9 back |
|---|---|---|---|---|
| PSA | 55/45 | 75/25 | 60/40 | 90/10 |
| Ace Grading | Better than 60/40 | Better than 60/40 | 65/35 | 70/30 |
| CGC (Gem Mint 10) | 55/45 | 75/25 | 60/40 | 90/10 |
| TAG (Gem Mint 10) | 55/45 | 65/35 (TCG) | 60/40 | 75/25 (TCG) |
| BGS (9.5 Gem Mint) | 55/45 | 60/40 | 55/45 | 70/30 |
| SGC (Gem Mint 10) | 55/45 | Not published | 60/40 | Not published |
Every company also has a stricter top label. Beckett's Pristine 10, CGC's Pristine 10 and SGC's Pristine 10 all want 50/50 on the front, and TAG's Pristine 10 wants 51/49. Our full centering tables go down to grade 5 for all six companies.
PSA 10 centering requirements
PSA's grading standards say a Gem Mint 10 should be approximately 55/45 or better on the front and 75/25 or better on the back. A PSA 9 allows about 60/40 on the front and 90/10 on the back. A PSA 8 allows about 65/35 on the front, with the same 90/10 back.
The front number changed in early 2025. Before that, PSA's page said the front of a 10 could be 55/45 to 60/40, and a lot of guides, videos and forum answers still quote the old range. Collectors noticed the new wording in February 2025; PSA said at the time that it described what graders were already doing. Either way, if you're working from the written standard today, 55/45 is the line.
How off-center can a PSA 10 be?
Less than most people think. A Pokémon card is 63 mm wide, and on a typical modern card the left and right borders add up to about 6.4 mm. At 55/45 that's 3.5 mm on one side and 2.9 mm on the other: a difference of about 0.6 mm. At 60/40 it's 3.8 mm and 2.6 mm, a difference of about 1.3 mm. So the gap between "a 10 on centering" and "a 9 on centering" is often less than a millimetre, which is why judging it by eye goes wrong so often.
Is 60/40 centering a PSA 10?
Not by the current wording. A 60/40 front is a PSA 9 on centering. The back is a different story: a 60/40 back is comfortably inside PSA's 75/25 allowance for a 10.
Ace Grading 10 centering requirements
Ace explains its method in its own blog post. It measures all eight border edges under a microscope, to a thousandth of a millimetre, and uses the worst pair of opposite edges. For a 10, the centering needs to be better than 60/40 on the front and better than 60/40 on the back. A 9 allows 65/35 on the front and 70/30 on the back, an 8 allows 70/30 and 75/25, and a 7 allows 75/25 and 80/20. Ace grades in whole numbers, so there's no 9.5 to fall back on.
Two things are worth knowing. First, you'll find other sites quoting Ace's 10 as 50/50 with a couple of percent either way. That isn't what Ace says, and it would make almost nothing a 10. Second, the back rule is the one that bites. A card with a 52/48 front and a 64/36 back is a PSA 10 on centering and an Ace 9. Ace's Grading Report shows the centering score on its own, so if you want to see exactly what they measured, that's where to look.
Why back centering catches people out
The blue border on the back of a Pokémon card is thin and moves around a lot from sheet to sheet, so plenty of cards with a lovely front have a back that's 60/40 or worse. PSA, CGC and Beckett all give the back more room than the front. Ace and TAG are much closer to their front limits. If you're sending to Ace in particular, measure the back before you pay the fee; it's the most common reason a clean-looking card comes back a 9.
A worked example: one card, six answers
Say you measure a card at 57/43 on the front and 63/37 on the back. Here's what the published limits allow on centering alone:
| Grader | Best grade centering allows | What holds it back |
|---|---|---|
| PSA | 9 | Front is outside 55/45 |
| Ace Grading | 9 | Back is outside 60/40 (front would pass) |
| CGC | 9 | Front is outside 55/45 |
| TAG | 9 | Front is outside 55/45 |
| BGS | 8.5 | Front is outside 55/45, which rules out 9.5 and 9 |
| SGC | 9 | Front is outside 55/45 |
Same card, same measurements, and the reason for missing a 10 is different at Ace than everywhere else. That's the main point: know which company you're sending to before you decide whether a card is worth it.
How to check your card before you submit
- Take it out of the sleeve. Sleeve and toploader edges look like card edges in a photo.
- Photograph it straight down on a plain, darker surface, or use a flatbed scanner, which gives the most accurate result.
- Open the centering tool on your phone or computer. It finds the edges and straightens the photo, then you fine-tune the lines with the magnifier.
- Measure the back as well. The tool combines both sides and shows the best grade each company's centering rules allow.
- Measuring with a ruler instead? Type your four borders into the manual centering calculator.
Centering is only one part of a grade. Corners, edges and surface count too, and graders measure under magnification. Use the numbers to decide which cards are worth sending, not as a promise of what comes back.
Quick questions
Does PSA grade the back centering?
Yes. A PSA 10 needs about 75/25 or better on the back, and a 9 about 90/10.
What is the worst centering for a PSA 10?
By the written standard, about 55/45 on the front and 75/25 on the back. Anything wider on the front is a 9 on centering.
Is Ace Grading stricter than PSA on centering?
On the back, yes, by a long way: better than 60/40 against PSA's 75/25. On the front Ace is slightly kinder, allowing up to 60/40 against PSA's 55/45.
What does 55/45 centering mean?
The wider border is 55% of the two opposite borders added together. A 3.3 mm border opposite a 2.7 mm border is 3.3 ÷ 6.0 = 55%, so 55/45.
Sending cards to Ace? Our Ace Grading discount code takes 5% off the submission. And if you'd rather buy one already graded, every slab in our graded cards collection shows its grade and certificate number.