Opening Book Settings

Opening books contain a collection of opening lines that you can use for analysis, or when playing against a chess engine.
There are different books for different purposes. For example, a chess engine might pick only the strongest opening lines.
When analysing a game, you would choose a book with a broader range of opening lines.

Lines from the opening book are displayed in The Engine Panel

Use the check boxes on the left to enable or disable an opening book.

Use the button to add a new opening book file. Jose can read files that were created by Polyglot, or Crafty.
For more information, see the download page at jose-chess.sourceforge.net.

Use the download button to download a file from the net.

Use the to remove a file from the list. Note that the file is not deleted from your hard disk.

Use the up and down buttons to change the order of books. This influences the set of selected moves.

Engine Play

The following options determine how opening lines are chosen from the book when you play against a chess engine.
Many chess engine are equipped with their own, private opening book. You can choose which opening book(s) should be preferred.

Engine private books can be configured here: Engine Settings .

Prefer user books

Prefer Jose's books (i.e. the books that are enabled in this dialog).
When a position is not found in the current book, fall back to the engine's private book, or let the engine calculate a move.

Prefer engine book

Prefer the engine's private book, if possible. If the engine has no private book, fall back to Jose's book.

User books only

Always use Jose's book. Disable the engine's private book.
Note: not all engine support this option, i.e. some engine will consult their book anyway.

Use no opening book

Don't use opening books at all. All engine moves will be calculated.
Note: not all engine support this option, i.e. some engine will consult their book anyway.