[Coja]

Of note, Most my doubles seemed to be Spanish names. And, had some really odd names as doubles - and not one "Smith" in my whole universe (28 teams major leagues, AAA, AA, A, and 80ish feeder teams).

In case anyone else is as insane as I am, and is building complete sets of cards for each season - here is what I did, and the formula I used in Excel to easily spot the doubles. Super easy.

Export to CSV. Open the "players" file into excel (or OO). Insert blank column into beginning, Sort by Last Name, second sort by First (with lables). Then place the following formula in the new column - @ A3. And, copy/paste into all the following A columns

For Open Office : (I think Excel is the same but all change the ; to ,

=IF(AND(H3=H2;G3=G2);"DOUBLE";"")

Wallah. This will give you all the doubles.
(Shows the whole league though - feeder leagues, players not on teams, all pro levels, even retired players. So, going through the first time could take a little bit. But, the rest of my years will just be newly created players doubling.)