Is the Black Belt or Fist Plate better?

Question

Both boosts fighting types but which is better on a fighting type Pokemon?

Answer 1

There are 2 differences between the 2 items. Fist plate causes fling to have higher base power, and it can't get stolen by an Arceus.
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This means black belt is better if your opponents are more likely to steal it and then use fling, and fist plate is better if you use fling or if your opponents are more likely to use an Arceus with an item-stealing move (or item-stealing ability, if you're playing a weird format where Arceus doesn't need to have multitype).

Answer 2

They're both equal. According to their pages, they both increase damage by twenty percent, which means that it makes no difference whatsoever. I believe the Arceus plates were just added into the game so that it can change type. Aside from the damage boost, the plates only have other effects if used by Arceus. If used by any other Pokemon, they just increase damage