We claim NCs for three of Knute Rockne's squads (1924, 1929, 1930) all before the AP and none were named '19 or '20.
Don is full of dog shit...here is a recognized list of NCs (we have a better claim to 1919) as Cal was named NC by the ones who were doing the naming of NCs at that time. https://www.ncaa.com/history/football/fbs
Billingsley is the one he's citing...as you can see below they didn't even exist until over 40 years after the year in question...and they didn't retroactively list ND as a 1920 NC until 2001 (81 fucking years after year in question) but Don fuckin Miller wants to claim the 1920 Natty even though ND doesn't.
FACT
Notre Dame claims 11 NCs...1920 ain't one of them.
Link: The Billingsley Report is a college football rating system developed in the late 1960s