Does foul play use a Pokemon's base stat?

For example if my umbreon uses foul play on a mew, and they’re both the same level, that benefits me since mew has a higher base attack stat. But what if I was fighting a level 5 mew or something and I have a level 100 umbreon.

In other words, does foul play simply recalculate my Pokémon’s attack stats using the opponent’s base stats?

Or does it simply just use whatever the opponent’s current stats are.

Cause the latter only seems useful if I was fighting Pokémon the same level or above.

Pleaselog inorregisterto add a comment.

No battle mechanic ever directly uses a Pokemon species’s base stat. For example, this is the damage formula.((2level/5+2)powerattack)/(50defense)+2In this formula, “attack” and “defense” represent the individual Pokemon’s stats, after taking into account stuff like level, IVs, EVs, and natures as well as the species’s base stats.sourceFoul play uses the same formula, except it uses the target’s physical attack instead of the user’s. It doesn’t directly look at base stats. However, it does use the user’s level in the damage calculation, so it will still do a lot of damage to a low-level target.Also, I want to make sure you know that foul play damage is affected by the user’s burns, abilities, and items, but affected by the target’s stat modifiers from stuff like swords dance and intimidate.source

It will be like using your opponents attack againts themselves. But if the Pokemon has low attacks, then it will result in a low damage.