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Chess - Programming - Polyglot Book Format - File Format

Polyglot files are usually named with a .bin extension.

The files contain one or more entries with each entry having the following information:

struct entry_t {
   uint64 key;
   uint16 move;
   uint16 count;
   uint32 learn;
};

NOTE: All integers are stored highest byte first (regardless of size).

Sometimes the file format is shown as:

struct entry_t {
   uint64 key;
   uint16 move;
   uint16 count;
   uint16 n;
   uint16 sum;
};