Behind the Slab #1: Impact of Whitening & Centering on Pokémon Cards
Looking at 4 edge cases that surprised us in our recent submissions.
I’m starting a new series breaking down grading results to see what we can learn. This first post focuses on Pokémon cards, specifically looking at the back whitening that’s extremely common on these cards.
So far in 2026 we’ve graded 168 cards and received 112 PSA 10s, good for a 66.7% gem rate, but that doesn’t mean we haven’t had some surprising results. This post will highlight a few of them.
For 3 of the cards, we thought a PSA 10 was unlikely but they graded as 10s anyway. For the last one, we thought a PSA 10 was highly likely, but the card graded as a 9. Let’s look at the cards and see what we can learn.
Note: Gem Probability is the percentage chance we give a card of grading as a PSA 10 before submission.
2019 Celebi & Venusaur GX #1 - PSA 9
Projected Gem Probability: 15%
Grading notes: Perfect besides tons of tiny white dots all around back borders (this was a test card for this specific issue)
This card was nearly flawless except for one thing: small white dots scattered across the back borders. I’ve marked up the top and bottom borders in the image below, which had the best lighting to see them clearly, but really these dots are everywhere. You’ll need to zoom in to spot them since they’re really small.
Normally we wouldn’t worry about dots this small, but there were so many of them that we dropped our probability estimate to 15%. I think this result tells us we can be more aggressive on this type of issue.
2025 Lillie’s Determination #184 - PSA 10
Projected Gem Probability: 25%
Grading notes: Top/bottom centering slightly out of range (43/57), back borders have some minor white dots
I’ve circled a couple of the white dots in the image, though there are more. All were very light, and we didn’t expect them to have much impact. The main issue was centering. We measured top/bottom centering on the front at 43/57 with the bottom being a bit larger, which is technically outside PSA’s 55/45 guideline.
The front borders on this card are extremely small, which makes centering tricky. Being slightly off in either direction can technically push them outside of 55/45. I’ve been thinking that visual appearance probably matters just as much as the technical measurement for cards like this, especially now that PSA added this note to their PSA 10 grading guidelines:
“*Centering Note: At the grader’s sole discretion, a small variance may be permitted on occasion based on the card’s overall eye appeal.”
2025 Mega Latias ex #181 - PSA 10
Projected Gem Probability: 25%
Grading notes: Top/bottom centering is slightly out of range (56/44), left/right centering also not perfect but still within 55/45. Back borders have some minor issues.
I’ve marked in red how we measured the top/bottom centering. As you can see, this one was slightly top-heavy but the visually the card doesn’t look bad. This matches the conclusion from the card above: for these small borders, visual appeal probably matters just as much as the technical measurement. There was also a white dot and a few other very minor issues on the back borders.
Despite all of this, it gemmed. I gave it just a 25% probability, but I guess I’m not shocked. We’ve been testing submitting things with imperfect centering lately, and the results are promising.
2019 Reshiram & Charizard #20 - PSA 9
Projected Gem Probability: 60%
Grading notes: Little/no flaws
This one surprised me. Looking at it in the slab now, I can see a couple possible flaws, although it’s nearly impossible to know what’s on the card versus what’s just reflection or marks on the slab itself without having my original notes in front of me.
The white spot on the left side of the back is almost certainly a minor mark on the card, though not one I’d expect to knock it down a grade. The edge wear visible on the right side would be enough to make this a PSA 9, although I’m not certain if that’s just lighting, or if it’s actually on the card. If that’s the culprit, we either missed it during pre-grading or the card got slightly damaged during shipping to PSA.