Paul Dickson has written  more than 50 non-fiction books and countless articles on subjects from toasting to ice cream to baseball to slang to Sputnik. He says he wrote this one when he became interested in learning more about the "covert aspects" of the game.

One way in which modern major league baseball differs from years past is the role of the umpires. Dickson says they are now coached to maintain a much lower profile than they once did.

Original Source