When checking for a Pokemon's IV, there is a selection: is the Pokemon powered up before?
Why and how does it matter?
Is it true that because if we never powered it before, then the Pokemon can only be at level that is "not half level"? That is, it can be only level 20, 21, 22, and so forth, and cannot be level 20.5?
So in that case, if in doubt, we can choose "it is powered before", because if we power it ourselves, then the level can be 20, 20.5, or anything, and therefore, be able to match for all possible results. Is that true?
Best Answer
When you catch a wild Pokémon, the level of the Pokémon will always be a whole number between 1 and 30. Each time you power up a Pokémon, the level of the Pokémon increases by one half (0.5). Therefore, if a Pokémon has never been powered up, there's no point in checking half levels when checking IVs.
If you indicate that the Pokémon has been powered up, then half levels are also considered.
This can Be illustrated using the IV Calculator, on the Poké Assistant website.
Marking the Powered field as No, results in only whole number levels being displayed in the results list.
However, if you change the Powered field to Yes, and calculate again. You'll see half levels included in the result set.