notes comparison improvements compare different file formats just plain PGN pgn2opg? CAT2PGN? cb (2pgn and the other way around) nic (2pgn and the other way around) En Croissant Sqlite .db3 format ChessBase CBH/CBV Scid 4 Scid 5 compare different datasets LumbrasGigaBase lumbrasgigabase.com pgn format lumbrasgigabase.com Scid 4/5 format