I've read reports about Hidden Power being changed to include the Fairy type, and possibly a major change in how it's calculated.There are a few of possibilities for how this could have been done, so there's a fair bit of data and tests to do to figure out. There's some small chance that there is no HP Fairy, so confirming that would be nice. To accommodate HP Fairy, the formula or method for determining Hidden Power has to change. It could have been done in three ways: 1) Modifying the existing formula to output a value from 0-16 instead of 0-15 This is actually what I see as most likely. The formula right now simply multiplies the output of its IV formula by 15 and then divides by 63, and then rounds down, and the way it works out you get a value from 0-15. If you just change that multiplier to 16, you have a functioning formula for a Fairy-type Hidden Power. It's also possible that a different method using IVs could have been implemented. 2) A totally new formula Yeah, to determine this it would have to be confirmed that IVs have no effect on what Hidden Power you have. From there, we'd have to isolate exactly which value DOES determine it 3) No formula at all It's possible a Pokemon is just given a random value from 0-16 on creation instead of a complicated formula. This will have to be the assumed case if possibility 2 is explored to its fullest and no pattern emerges. Tests Needed: - Confirm that Hidden Power Fairy exists. (Single Step) Test out random hidden powers until you get one that is Fairy. There's an HP Guy. He's in Anistar City, right next to the Clothes Store. (Thanks Moogle!) - Confirm that Hidden Power is still dictated by IVs (Single Step) Obtain multiple Pokemon with identical IVs. (Breed!) and see if they have the same Hidden Power. If we can confirm a few times that it is the same, then we can conclude that it is determined by IVs. If in any case it isn't, and the IVs are for sure the same, we can conclude they aren't. - Provide IV Values for each Hidden Power type For this process you need to make sure you know the Pokemon's exact EVs (preferably no EVs). IV calculators are only accurate if valid information about base stats and EVs are available for the Pokemon. They also work better when the Pokemon is at a higher level. (Step 1) Determine which type of Hidden Power you have. Be careful not to confuse types. (Step 2) Calculate your IVs and provide these values to us, along with the Hidden Power associated with it. With these values, we can see if we can put together what the new formula is. We need as many data sets as possible to figure this out. --- Calculating IVs is best done with old Pokemon, as we have more accurate information on their base stats. Be aware that some base stats have changed ( http://www.serebii.net/xy/updatedstats.shtml (this list is not comprehensive) ) and making certain that the Pokemon you're testing has proper base stats ( http://pokemon-online.eu/forums/showthread.php?22722-Collecting-Base-Stats ) is key to getting accurate results. There are several IV calculators. One that can simply take an input of Base Stat rather than Species would be preferred, since we may need to find a Pokemon that has been confirmed to keep its old base stats in X/Y for it to actually be compatible with old calculators.
You don't need to test Hidden Power in battle btw, you can just talk to the HP guy and he'll tell you. He's in Anistar City, right next to the Clothes Store. Absol - #359 (Naughty) HP: 31 Att: 31 Def: 29 SpA: 31 SpD: 31 Speed: 31 PO claims this is Hidden Power Fairy. It's Hidden Power Dark in game. That's what it would be in Gen 5 too. Gonna do more Gardevoir - #282 (Modest) HP: 20 Att: 20 Def: 20 SpA: 31 SpD: 20 Speed: 31 Should be HP Ghost according to PO It's Bug in game Lilligant - #549 (Modest) HP: 6 Att: 31 Def: 31 SpA: 31 SpD: 29 Speed: 29 Should be HP Dark according to PO It's Dragon in game
These all match up with the old formula. Maybe HP Fairy isn't a thing. It would be helpful if everyone tests out all their pokemon to see if anybody can ever get HP Fairy, until then collecting a lot of IV data may not be needed. (It'd still be good to make 100% sure the formula hasn't changed, but it seems unlikely at this point)
I don't believe that option 1 is likely/possible. The way Hidden Power is calculated involves taking a value from each IV (the first bit of each IV) and then plugging it into the formula. This effectively creates 64 different possibilities of Hidden Power. Each IV has two possibilities, there are six IVs, 2^6=64. 64 is perfectly divisible by 16, but not 17 and changing the multiplier does not increase the possibilities at all since it will still have the same number of outputs as there are inputs. Unless of course some IVs will be slightly more likely than others (3 or 4 possibilities each).
The number is never divided by 16 (or multiplied by it, for that matter) but rather multiplied by 15. The formula is rounded down, there's never any perfect division going on. The formula outputs a number 0-63, and then multiplies by whatever you want, then divides by 63. So you essentially end up with a number from 0/63 to 63/63, and then multiply. Changing the multiplier absolutely increases the number of "outputs" (it increases the value the formula spits out) This is how I would have coded it if I was doing this. In fact, this is the formula currently implemented in the PO XY Beta. Well, we need HP Fairy confirmed still. Let's see if it actually exists.
Hi. I am no expert but I did the one part of this I am proficient at, the grunt work. I tested 150 random Pokémon from my boxes (I'd do more but it's tedious as fuck) for hidden power types, I encountered every type a minimum of 4 times (probably more tbh) but I never once encountered Fairy, now I could just be unlucky but that'd be a 0.011% chance, a long with the fact that absolutely nobody else has reported and confirmed HP Fairy, I think it not existing is a very strong possibility.
I think we can safely say there is no Hidden Power Fairy at this point. It's already been removed from the next version of the PO XY Beta, so we can just totally not worry about it. The formula apparently hasn't changed, and nobody can confirm it. I think we are DONE here. Nice testing!