1820 large cent small v large date
Per usacoinbook online, a curl 2 is the characteristic for a small date, a knob 2 for a large date. Ie two types of obverse.
Per bowers guide book, the determining characteristic is the '0', and both large and small date has both types of '2'. Ie four types of obverse.
Can anyone shed light on this?
Ignore for now the 1820/19.