out of book
(chess) No longer following commonly played theoretical lines analyzed in opening books; in territory unfamiliar to one or both of the players.
Antonym: in book
The terrible thing about the Internet and Amazon is that they take the magic and happy chaos out of book shopping. The Internet might give you what you want, but it won't give you what you need. Tom Hodgkinson
Day by day, religious conceptions grow less and less intense. Day by day, the old spirit dies out of book and creed. Robert G. Ingersoll