EV's on Tyranitar under lv100

[Spike]

Okay, so I caught an Adamant Pupitar in Black 2 and it has great IV's. I wanted to EV train it but my friend told me that for Flat Battles since the Pokemon are downgraded to 50 (the Pupitar is level 55) that I needed to EV train it differently. I read a guide on Google by searching for "5th gen EV training guide" and I'm confused about what I need to do. I did plan on playing in a VGC this season.

The guide speaks about EV training for Level 50 and says:

Stat gains for EV's are halved.
And
IV/2 + EVs/8 must be a whole number.

Does this apply to my Pupitar at level 55? I was going to do 180 Hp, 252 atk, and 76 spd, following the traditional divisible by 4 rule and assuming it would auto correct for a VGC. What do I do now? How many EV's do I use for this Pupitar now to equal what I have above if this applies to me? I haven't read this in other guides and I'm a little confused.

If the IVs on Ttar are 31 HP, 31 ATK, and 31 SPD. I can't seem to get my math to come out properly.

 

[pokemonrocks777]

The ev's should still be the same at lv 50 and lv 100. the Stats do change to the level 50 Base your evs do not change. it is just a "weaker" lvl 100 pokemon. it all depends also on hoe you want to run your t-tar

 

[Kayle]

The actual stat formula for every stat other than HP is as follows.


STAT = 5 + ((((base * 2) + IV) + EVs/4) * (level / 100))

The IVs and EVs remain constant (well, other than EV training) on a Pokemon. When you level the Pokemon up or down, only the level variable changes.

So if your Pupitar has 252 Attack EVs (and a neutral nature) at level 55, the stat would be:

5 + ((((84 * 2) + 31) + 252/4) * (55 / 100))
5 + (((168 + 31) + 63) * 0.55)
5 + ((199 + 63) * 0.55)
~149

...but at level 50, the stat would be 136, and at level 100 the stat would be 267. VGC's auto-leveling whatever doesn't do anything to your EVs or IVs. They just have a less significant effect on the final stat.

Given that your Pupitar is adamant you just multiply the final stat by 1.1, reaching a stat of 163 at level 55, 149 at level 50, and 293 at level 100.

EDIT: The reason your friend tells you to EV train differently is because of the flat leveling of VGC, versus the everything-is-level-100 mentality most EV guides will assume.

If we just assume that level is always = 50, the formula above simplifies to:

STAT = 5 + ((((base * 2) + IV) + EVs/4) * (50 / 100))
STAT = 5 + ((((base * 2) + IV) + EVs/4) * 1/2)
STAT = 5 + (((base * 2) + IV) + EVs/8)

Whereas if we assume level is always = 100 then, clearly, we get:

STAT = 5 + (((base * 2) + IV) + EVs/4)

So for level 50 battles your EVs should be divisible by 8 (anything else won't matter)... at level 100, they can be divisible by 4.