I always find it interesting comparing 1st Edition Base Set with Shadowless Base Set. The submission numbers for most of the holos are very similar, yet the 1st Edition versions usually have more higher grades:
Card
1st Edition (PSA 10)
Shadowless (PSA 10)
Alakazam
1092 (85)
938 (29)
Blastoise
1619 (98)
1553 (41)
Chansey
1117 (46)
843 (14)
Charizard
2753 (121)
3448 (54)
Clefairy
1007 (64)
765 (26)
Gyarados
1046 (85)
1330 (59)
Hitmonchan
971 (54)
1092 (40)
Magneton
1028 (65)
886 (54)
Mewtwo
1052 (80)
1336 (66)
Nidoking
1122 (91)
936 (43)
Ninetales
956 (67)
1238 (46)
Poliwrath
1019 (98)
872 (44)
Raichu
1241 (87)
822 (24)
Venusaur
1442 (134)
1464 (88)
Zapdos
1197 (125)
837 (57)
Interestingly the PSA 9 numbers for both sets are also relatively similar (i.e. 650 PSA 9 1st Edition Charizards vs 600 PSA 9 Shadowless Charizards). Whilst I’m sure there are a lot of factors at play I feel like it could be argued that PSA used to be more lenient or that 1st Edition cards had a higher quality print run.
I feel like a Shadowless PSA 10 set would be a much greater achievement than a 1st Edition PSA 10 set.
This is interesting but could be due to people consistently sending 1st edition holos for 20 years but only sending shadowless in the later more recent years. If you believe PSA grading has become slightly more strict on PSA 10 cards in the past couple years, it could have an effect on the pop reports.
Even if the psa being strict is the case, it seems hard to make up the difference. 121 out of 2.7k charizards in psa 10 and only 54 out of 3.4k shadowless charizards in psa 10. Kind of a crazy difference but regardless I’d agree a shadowless psa 10 set would be far more impressive.