My theory?
I suspect the two large collections (Promise and Oregon Coast) HA dumped on CCS and CGC in the 1st/2nd quarter of 2020 are probably the main culprit.
My guess it was an all hands on deck type of affair, pulling graders from every tier to assist. After all, HA had two big auctions coming up in September and January, so my guess is that was CGCs primary focus for 3-4 months.
Once the collections were finished, they focused on getting moderns caught up, as that comprised the majority of their ungraded population accrued during the Summer of Speculation.
Again, just my theory. I’m probably way off 🫣