Note: I did not include to catch the Legendary Birds, for the fact that they are extremely rare to spawn. It would take hours upon hours to do so for all the areas they spawn in.
To be able to catch the Rare Pokémon, you need to build up a high Catch Combo. This is done by catching one kind of Pokémon repeatedly. For example, If I catch 12 Pidgey in a row, my Catch Combo will be 12. The higher your Catch Combo, the more likely a Rare Pokémon will spawn.
For maximal encounter rate, you need to build a Catch Combo of 31 or above, this will give make it 6 times more likely a Rare Pokémon will appear. Also, using the Lure Items will help tremendously so be sure to buy a lot.
Pokémon: Let's Go, Pikachu! and Let's Go, Eevee! Statistics For velby
There are 245,458 views in 125 videos for Pokémon: Let's Go, Pikachu! and Let's Go, Eevee!. About 3 hours worth of Pokémon: Let's Go, Pikachu! and Let's Go, Eevee! videos were uploaded to his channel, or 5.67% of the total watchable video on velby's YouTube channel.