How accurate are pop reports for PSA 10 rate when opening?

General
1

I got curious because of a post I made yesterday where I tried to do some calculations based around breaking unlimited base boxes and their PSA 10 rate, I just made a guess that 1/4 of the cards would come back PSA 10 and the others PSA 9.
Today I checked the pop report and came up with the following.
Unlimited Base

Now there’s definitely some factors at play that muddy things:* The further a grade is off PSA 10, the more likely it came from a collection rather than a box break.

  • The most expensive cards have higher odds of having an inflated PSA 9 count due to cracking and resubmitting them multiple times for a 10.
  • The fact that cards may not get a 9 nor a 10 is completely ignored.
  • Different cards may have different PSA 10 odds due to their positioning on the sheets.
  • Some of the cards also come from Theme Decks.
  • Also, Machamp should be excluded when breaking boxes.

Can we draw any conclusions based on this? Even if only for rough numbers.
Some extra numbers, all excluding the Machamp, and with unweighted odds:* Average PSA 10 odds: 21%

  • Average PSA 10 odds Charizard/Blastoise/Venusuar excluded: 22%
  • Average PSA 10 odds Gyarados/Hitmonchan/Mewtwo/Ninetales excluded: 20%
  • Average PSA 10 odds both top 3 and theme deck holos excluded: 16%
2

Zard data unreliable. I wouldn’t be surprised if 1 in 2-3 psa 9 zards are cracked and resubmitted. Also I reckon the true psa 9 zard pop is low 3000s

3

With that data it wouldn’t be unwise to assume the real Charizard pop 9 is similar to the other base starters in the 1500+ range. It can’t be absurdly higher I imagine as wee have seen tons of full box breaks on unlimited base and aren’t seeing zards being pulled more often than others on a consistent bases.