Holy moley!!!
I believe I have solved this riddle.
Look closely at where
Roberto Clemente's name appears on the sheet. First, how much lower it sits than the card directly above his and the
Steve Blass card
(and quite a few others on the sheet).
Also look at the amount of white space between each player's name and the large capital
'E' below them. It is entirely inconsistent, and
Clemente is clearly one of the anomalies — his name comes quite closer to it than a lot of the others
(look at the vast white space there on the card directly above his, as well as others).
1965easthillsclementeprintsheetcloseup.jpg
Conclusion: if the sheets were all cut the same way, then it would be an absolute rarity to have cards where
Clemente's name
(and others, of course) were
NOT close to the bottom borders.
I imagine tracking down players who have similar name placements to
Clemente would show their cards to also be off-centered the vast majority of time.