Simple

Description

All stat changes applied to the wielder are doubled. Set boosts (such as those received by Baton Pass or copied via Psych Up) are not doubled. Pokemon with Simple are still limited to a maximum of 6 boosts to any given stat.

Competitive Use

No Pokemon that are decent in OU these days have Simple, so while it is a fantastic ability, no Pokemon can take advantage of it. Furthermore, it does not double the effects of existing stat boosts, so your dreams of Baton Passing a single Tail Glow to Bibarel and sweeping are just a fantasy.

Found normally

Pokémon	Type	Tier	Abilities	HP	Atk	Def	SpA	SpD	Spe	BST
Bibarel	Normal / Water	NU	Simple / Unaware / Moody	79	85	60	55	60	71	410
Bidoof	Normal	LC	Simple / Unaware / Moody	59	45	40	35	40	31	250
Numel	Fire / Ground	LC	Oblivious / Simple / Own Tempo	60	60	40	65	45	35	305

Found in Dream World

Pokémon	Type	Tier	Abilities	HP	Atk	Def	SpA	SpD	Spe	BST
Swoobat	Psychic / Flying	NU	Unaware / Klutz / Simple	67	57	55	77	55	114	425
Woobat	Psychic / Flying	LC	Unaware / Klutz / Simple	55	45	43	55	43	72	313