Opening Book

Concept:

In Arena you can load one main book. The content of the main book is shown on the "Book" tab sheet as an alternative to the move list or together with the move list in the "Mix 1" tab sheet. In this list you can see all moves, priorities, probabilities etc. This book is called here "Arena Main book". All engines will use this book, if they are configured to do so in the engine configuration dialogue.

Additionally you may define a separate book for every engine. This book will be read before every move, when the engine is to move. This book is called here "Arena Engine book". These settings can also be changed individually for each engine in the engine configuration dialogue.

Arena Main books and Arena Engine books have the same Arena-specific file format and can only be handled by Arena, not by the engines.

The previous statements refer to Arena's own book management. A different topic is that many engines might use their own internal book. This book is here called "Internal Engine book". You can set this book for UCI Engines in Arena in another dialogue. There is no standardized way of selecting a book for WinBoard engines, refer to the documentation of the engine.