Let's say we wanted to ev that Azumarill in sun and moon:
Azumarill
EVs: 164 HP / 252 Atk / 92 Spe
I would give it 10 hp ups, 10 proteins and 9 carbos. Faint 2 pokemon in the wild for 2 speed evs, probably the regional bird. Can we get 64 in the plaza store and deposit in the pokepelago until it reaches 252 in atk?
Gotta test the berries as well.
So I've taken it upon myself to do some testing now with EV related stuff, yay!
First off, let's break down Poke Pelago:
---------- Isle Evelup ----------
This is the name of the island in the Poke Pelago that lets you train EVs. It also allows you to gain experience, but that's not the point of this and I didn't test it. First I'll explain how it works.
At level 1, you can have one "group" train. A group is 1-6 Pokemon from your boxes. You place some Pokemon into the group then select a drink/training regimen. The options are exp and the six stats. Then you select an amount of "play sessions" which each take 30 minutes. By using Poke Beans, you can speed things up. Things move at double speed while Poke Beans are in effect, meaning while using Poke Beans you can shorten sessions to 15 minutes each.
At level 2 you unlock a second group, at level 3 you'll unlock a third group. This means that at level 3, you can have three different types of training sessions going on at once with up to 6 Pokemon in each. A Pokemon can only be in one group, so you can't train one in three different ways at the same time.
"But what about the EV rate?" you ask? Well, at level 1 you'll receive 1 EV in the stat per "play session" so every 15/30 minutes you'll earn 1 EV. At level 2 this changes to 2 EVs and, while I haven't checked this because I don't have the beans to reach level 3 yet, I'm assuming level 3 will be 3 EVs.
With the doubled speed provided by using poke beans, that means you'd get 4, 8 or 12 EVs per hour depending on the level of your island. Without the speed boost, you'll get 2, 4 or 6 per hour. So... yeah...
Moving on!
---------- Festival Plaza ----------
So I checked two types of stalls here. One was a 1* Bouncy House, the other was a 1* Food Stall that serves EV related meals. You can only use a given option from these stalls once per day. So, I could train both Sp Def and Def in the bouncy house today, but only once each.
The Bouncy House cost me 5 FC to do a session and earned 4 EVs in the stat. The food stall cost me 20 FC per meal for 10 EVs per stat. If we assume these numbers double for a 2* stall, then the bouncy house would be 8 EVs and the food stall would be 20 EVs. And again possibly 12 and 30 at 3*? This is speculation as I can't test what I don't have.
So that's that...
---------- EV Berries ----------
These still reduce EVs by 10 each.
---------- Vitamins ----------
These still increase EVs by 10 each, up to a max of 100 in the stat.
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So what about the example quoted above?
Vitamins used to get to 100 in each HP and Attack, and 90 in Speed. This'll total 290k as they're 10k a pop. Alternatively, it'll cost 58 BP, as they're 2 BP each.
You could get 64 HP via the plaza, but it would likely require multiple stalls and would be a one-off for the day.
Then that 152 Attack via Isle Evelup is gonna take 152 play sessions at level 1,76 sessions at level 2 or 51 sessions at level 3 (under the assumption that level 3 is 3 EVs per "session"). That's gonna take 38 or 76 hours at level 1, 19 or38 hours at level 2, and 12.75 or 25.5 hours at level 3.