Master.dat is a binary database file. That's the final file of the database, it's generated with the Editor to be loaded by the game.
char - database type - XDFB (maybe X Database File Binary?) unsigned int - version (depends on FM version), example: 0x2013000A unsigned int - size (total size of uncompressed data) unsigned int - uncompressed file hash unsigned int - unknown, usually 6 unsigned int - unknown, usually 0 char - compressed data
The data is compressed with some 'LZ' algorythm (it's often used in FIFA games).
Uncompressed data structureEdit
unsigned int - system (OS) timer value (when db was exported) Country - countries
unsigned int - number of league levels in country (max 32) wchar_t - country name (with translations), null-terminated wide strings.