The Sagan
Standard, ECREE - Extraordinary Claims Require Extraordinary Evidence. Carl Sagan
applied this to the
search for extraterrestrial life, but it can be
applied as a universal rule of logic - sort of the
flip side of Occam's Razor.
When I began in this hobby I used to look at my very worn coins and try to see any indication of an unlisted variant.
Hope sprang eternal. Now when things are difficult to read my default assumption is it will be the most common solution, if this is
definitely ruled out then the second most common, etc.
SC