There really is no full proof way to differentiate between the two as there was no year tagging I am aware of. You can narrow it down only by examining the numbers. The following numbers only appeared in 1971: 34, 45, 48, 32, 72, and 4. The numbers that are exclusive to 1972 are: 46, 13, 19, and 47. All other numbers used in 1970 were also used in 1971. I am no expert on uniforms so I would defer to anyone with more knowledge or information. Nonetheless in the last couple of years I missed out on a #2 shared by Patek and Hernandez and a #18 worn by Davalillo and Alou. There have been a couple of 8s and a 21 but I don’t live in that tax bracket.
