A look at the consistency of PCGS grading over a period of time

dbldie55

I have been keeping a data base of PCGS pops for Liberty Nickels for years now. I then have a page that will let me diff any two months to see changes. Many times, the changes in 1912 S pops were so great, I thought I made mistakes doing the numbers. After the recent flap over the "letter", I now know this was due to a few gem rolls getting graded.

Now, below are the numbers for almost the last 2 years. First column is year/month, second is MS65 pops and last is MS66 pops. I include the + counts with the non plus counts.

You can see the numbers jump both ways. When the "letter" came out, MS66 pops were 50 and today it is 34 (so even down from last month).

What this is telling me is someone one or group is cracking and re-submitting these coins. They are then returning the old inserts to fix the pops. Given this, and these numbers, it actually looks like PCGS has been remarkably consistent with their grading. (this is assuming many are coming back in the same grade as these numbers seem to indicate)

201506 287 23
201507 304 23
201508 335 23
201509 363 25
201510 281 28
201511 307 30
201512 331 30
201601 352 33
201602 374 32
201603 385 33
201604 421 35
201605 436 38
201606 341 38
201607 359 41
201608 394 47
201609 401 49
201610 338 50
201611 342 50
201612 347 50
201701 305 50
201702 296 36

Sonorandesertrat

Hmm. Comparing the highs vs. latest figures for both 65 and 66, and factoring in 2-3 'gem' rolls (call this 100 coins), more than 200 either dropped out (due to transitions to flanking grades) and/or people were sitting on a lot of inserts and turned them in within the last year. This is quite a high percentage of the totals for either grade. Even if none of the coins in those rolls were gem, the drops in populations are striking.

cameonut2011

I would like to see those numbers for a 10-15 year period (or even a five year period)!

TwoSides2aCoin

It's studious what you're tracking....but don't get overwhelmed by statistics

joebb21

Perhaps someone was holding onto tags- or perhaps the pops were lowered for other reasons. I personally think the pop is significantly higher based on how many pieces Ive handled.

messydesk

There's also crossing to NGC that could be coming into play here.

cameonut2011

@joebb21 said:
Perhaps someone was holding onto tags- or perhaps the pops were lowered for other reasons. I personally think the pop is significantly higher based on how many pieces Ive handled.

Buybacks?

Elcontador

Pops of Liberty Nickels in PC 6 have exploded in the last 3 years, especially for the so called "better dates." Across the board. Prices have cratered. I've seen a number of the newly made coins, and personally, would not buy into this market, even at the new reduced prices.
In this light, I don't think you can discuss pops and consistent grading in the same sentence.