Book Player

(n.) = ?
Ex: He selects a medical textbook library, slots the disc into his book player and starts to read, pausing occasionally to write in comments with a stylus.

Ex: He selects a medical textbook library, slots the disc into his book player and starts to read, pausing occasionally to write in comments with a stylus.

A person who memorizes opening theory. Taking someone "out of book" refers to avoiding theory and playing a new or unorthodox move, which may confuse a book player.