>>33955963Blue's encounter rates "generally" match up to Red and Green. For example, the Caterpie line and Weedle line are considered opposites in Red and Green. Every time you encounter a Weedle in Red, it's like encountering a Caterpie in Green, and the reverse is also true. Blue matches either Red or Green for various counterpart Pokémon. I believe it matches Red for the Caterpie and Weedle lines. There are also oddities. In Blue, you can find Ditto in Rock Tunnel, Lickitung in the Safari Zone, Jynx in the Seafoam Islands, etc. Cerulean Cave has a new layout, NPC's trade different Pokémon, the tileset has been updated, and the Pokédex entries are new.
International Red and Blue basically took Japanese Blue, translated it (hence mistaken trade dialogue and Blue Pokédex entries), added the Red and Green trade Pokémon, and then split it in two with Japanese Red's encounter rates in international Red and Green's encounter rates in international Blue.
