Polyglot Opening Book Creator

Create Polyglot-compatible BIN opening books from PGN game files for use with compatible chess engines and interfaces. Choose how many plies to include, set a minimum move frequency, select one or both sides, and download the generated book. The tool prepares opening-book data; it does not analyze positions or replace an engine.

Download v0.2.0

Download CAISSA Book Creator v0.2.0 (Portable ZIP)

Online PGN → BIN Service

Choose a .pgn file of up to 25 MB, apply the available options, and generate a Polyglot .bin file. The file is uploaded to the CAISSA builder service for processing.

Choose PGN file

Maximum plies Minimum occurrence count Side

Build Log

[ready] Waiting for PGN upload...

What Is a Polyglot Opening Book?

A Polyglot opening book is a binary opening-book format used by compatible chess engines and interfaces. It connects board positions with candidate moves and associated book data such as move weights. During the opening phase, compatible software can consult these stored choices before relying fully on engine search. The book is not a chess engine: it does not evaluate positions, calculate variations, or choose moves outside the entries it contains.

What Is a BIN File?

.bin is the usual filename extension for a Polyglot opening book. The data is compact and machine-oriented, so it is not intended to be read or edited like a text document. Test the generated file in software that explicitly supports the Polyglot book format. A BIN extension alone does not guarantee that an unrelated application will understand the file.

PGN vs Polyglot BIN

PGN is human-readable text commonly used to store complete chess games, headers, and move sequences. Polyglot BIN is an engine-oriented opening-book format that stores positions and candidate moves efficiently. This tool reads supported PGN game files, counts the moves reached from each position under your selected limits, and writes those results as a downloadable Polyglot BIN book. The generated book does not preserve the PGN as a collection of readable games.

How to Use the CAISSA Polyglot Tool

Choose a .pgn file no larger than 25 MB.
Set the maximum plies, minimum occurrence count, and side to include.
Select Generate opening book. CAISSA uploads the PGN to its builder service and validates the games it can parse.
When the build succeeds, the BIN downloads automatically and a Download BIN link remains beside the output summary.
Load the file in a compatible engine or chess interface and test its opening choices.

Important Compatibility Notes

Polyglot support and configuration vary between engines and graphical interfaces. Keep the original PGN and backups of any existing book before replacing files. Book behavior depends on its entries and weights as well as the receiving software’s book settings. Test the result before using it for a tournament, automated match, or other production workflow.