This is a general page containing links to my various Monotype Run articles.  If you want to do a Monotype Run (formerly Single Type Run) in Pokemon check out the chart and the various articles below for more information.

Introductory Article (which are the best games and types overall to do a Single Type Run)

Games
Red/Blue/Yellow
Gold/Silver/Crystal
Ruby/Sapphire/Emerald
FireRed/LeafGreen
Diamond/Pearl/Platinum
HeartGold/SoulSilver
Black/White/Black2/White2
X/Y
OmegaRuby/AlphaSapphire
Sun/Moon
Ultra Sun/Ultra Moon
Pokemon Let’s Go Pikachu and Eevee
Sword/Shield
Scarlet/Violet

Types
Bug
Dark
Dragon
Electric
Fairy
Fighting
Fire
Flying
Ghost
Grass
Ground
Ice
Normal
Poison
Psychic
Rock
Steel
Water

Rules

1.   You can only catch and train Pokémon of a certain type.  Once you capture your first Pokemon of that type, disregard any previous Pokemon on your team.
2.   If a Pokémon evolves to said type you may train it but evolve it ASAP.
3.   No out-of-game-trading allowed, in-game trading is fine
4.   If a Pokémon changes to said type via Mega Evolution you are allowed to train it provided you Mega evolve it every time.
5.   Only Pokémon caught before the Elite Four are counted.