Rick Ankiel first_name comes up as Richard
Issue No. 133
Rick Ankiel first_name comes up as Richard. Not sure if you are using a library to interpret first names, but this could potentially be an issue.
You probably want "display_name" instead. See also /api/issues/103
From the API documentation:
Player's legal first name. Keep in mind, some players are commonly known by their middle name, nickname, or shortened version of their first name