IV adds to the base stats, so the effect of IV is proportionally smaller on mons with very high base stats. e.g. in Arcanine, base attack is 230, so a 15 IV attack stat would give it 245. In terms of attacking power (i.e. actual damage to opponent done per quick/charge move) the attack stat is the most important, but as you see, in this case 15 att IV would mean only 6.5% more damage than 0 IV. Defence has a more effect proportionally for Arcanine, because the base is only 180, so zero versus 15 def stat would be a little over 8% better defence (reducing the damage done per attack by opponent). One interesting thing is that def and stam count only 50% as much towards CP, so poor ATT IV will have the biggest effect on CP. But don't rule out one with a weak ATT stat for gym levelling in particular: In that case a 0-0-15 can be useful, particularly if the base Att/Def is already decent (e.g. Vaporeon) because it means you can have a mon with lower overall CP (which gives you more prestige against opponent, as long as your other 6 have equal or weaker CP), but maximum possible HP for its level - useful when taking on a defender with double your CP.
What is missing specifically?
Assuming best moveset for a same species of Pokemon, what is the impact of zero portion of attack or defense of IVs to the overall attack or defense power?
E.g. in terms of attacking power, what impact between two arcanines of same moveset and similar CP, but different IVs
Att/def/sta = 15/0/15 vs
Att/def/sta = 15/15/15
Thanks
Answers
Dps is partially calculated by attack stat+IV / 200.
In your example it would be 245 / 200 = 1.225 and that's your modifier for move damage with some other factors, the whole equation is in the damage mechanics section, i'll copy/paste though.
Damage = Floor { Attack / 200 * Move Power * STAB } + 1
True DPS = Damage / Duration
So this true dps applies to attacking a pokemon with 200 defense, if their defense is higher/lower than 200 it'll act like a modifier to damage too.
For your Arcanines it would be:
200 / 195 = x1.025
200 / 180 = x1.111 damage taken
You don't really need to overcomplicate it by considering DPS. The division by 200 in the equation is only necessary to calculate true DPS for a given attack but because its a constant, the actual attack/def damage done/taken (irrespective of the move strength or STAB) is linearly proportional to the attack/def stats: hence on a mon with a 100 base attack like Nidoran fem a 15 IV gives a 15% boost. But it has proportionally less impact on elite mons like Arcanine where the base stats are already very high. I'm on team Mystic, so Blanche is lying to me when I appraise a poor IV Arcanine as "unlikely to make headway in battle" - with the right moves and if it evolves from a Growlithe that is already well powered up it is still a devastating weapon compared with a 15 IV Nidoran fem!
Energy from damage matters to defenders who have double HP and also use quick moves less often. Attackers gain most of their energy from using attacks, not taking damage.
You're going to end up doing less damage overall because your pokemon will faint sooner rather than do more damage because you're able to use a charge move slightly sooner from taking more damage.
There are a lot of variables, and how you use the mon will determine the best IV mix to use.
As others have said, a 15/0/0 mon will have the same CP as a 0/15/15 mon
For general strenth and dmg output, you would certainly want the 0/15/15, because your dmg taken would be reduced more than the increased dmg you'd get from 15/0/0
It's important to distinguish between prestige Pokemon and non-prestige Pokemon.
For your best attackers that you're going to max (like Arcanine) you want to max IV's all around. Go for highest overall total
For prestige mons, Since the dmg calculation involves Pokemon level, and not just stats (this is important), it means that lower stat mons will be better than higher stat mons at the same CP (but obviously not the same level). This means that higher level, lower stat Pokemon make the best prestige Pokemon b/c they use their CP more efficiently.
For example, with a high ATK stat mon like Flareon vs. high DEF/STA mon like Ninetales, holding CP constant at 1500 CP w/ 15/15/15, Flareon will be level 20, and Ninetales around 24.5. Ninetales' TDO (Total Dmg output) will actually be about 20% higher than Flareon's.
However, if you max them both out at level 30, Flareon will pull ahead due to higher overall stats in general.
You also need to take into account dodging. If you dodge every attack, even quick moves, then the 15 ATK IV will have a proportionally higher impact. Tough to math this out.
Also, for gym defenders, you want to maximize ATK IV, b/c you want to maximize CP. This will make sure your mon stays as high on the gym as possible. As said previously, a 33% IV mon with 15/0/0 has the same CP as a 67% with 0/15/15
Lastly, another thing you should consider is the formula favors a relatively similar DEF/STA for max benefit. So having 0/8/7 is better than having 0/15/0 or 0/0/15
HTH!
TL;DR
Generally, 0/15/15 is better than 15/0/0 and will have the same CP
The only situation where ATK is most impt is for gym defenders.
For the Pokemon you plan to max, you want the highest IV possible.
Several of the online IV calculators will show you the possible stat ranges for pokemon at a certain level.
https://thesilphroad.com/research
SilphRoad IV rater is quick if you are just looking for ranges of CP and HP values that are possible for a pokemon at a certain level. They haven't incorporated the pokemon rating information though, so actual IV data can be imprecise.
https://pokeassistant.com/main/ivcalculator
PokeAssistant IV calculator breaks down exact stats (Atk, Def, Stm) separately and shows the outer ranges for 0% IV and 100%, but the input is a little sloppy on mobile devices
At level 30, Arcanine possible ranges are
0% IV:
Atk 230, Def 180, Stm 180, CP 2216, HP 131
100% IV:
Atk 245, Def 195, Stm 195, CP 2557, HP 142
For most pokemon, the difference between 0% and 100% IVs is a couple hundred CP. This is mainly important if you are powering up pokemon to as high as you are able at your current level to put into gyms.
A bad IV pokemon with an offensive move set is fine because it can still be used for training team gyms without spending any stardust on it, or for attacking if it is already a high enough level. What I absolutely do not want though is a bad IV pokemon with a defensive moveset. Since movesets are random for evolved pokemon though, I generally aim to only evolve pokemon with 80%+ IVs. If I get an offensive moveset, then I can then choose to leave it at that level for training, or power up for attacking. If I get a good defensive moveset, I already know it has good IVs so I can power it up to put into gyms. If it gets a horrible mixed moveset, well, that's always disappointing.
