The highest stat boost you have ever gotten?

[Fire Wolf]

For me, it was a.... +51 on Sp.Attack with my Shelgon and +44 with the same Shelgon on Speed.

 

[GlitchCity]

+8 on the attack of machoke in my emerald, thats all I can remember

 

[The Bringer!]

+23 for my heatran's special attack =D

...but I wanna see someone rare candy something to level 99, then complete all their ev training on that one level xD
It'd be like +63 or something if they max out a stat o3o

 

[Idiot!]

Insert random filler here.

 

[Silhouette]

I got a +21 in Sp. Attack for my Azelf.

 

[Sydian]

+9 for someone on something. Ha, I can't even remember. It's been a while since I've played a main game in a while, to be honest.

 

[bit.trip void]

I think it was plus 12 for a Hitmonchan tbh. Fire Red.

 

[Moltres111]

I just got a new nice boost;

+31 Sp. Atk on a Mewtwo I recently traded for my Palkia via the GTS. It got +15 on the level before, so I think i'm soon done with the Sp. Atk.
(This thing has friggin ROCK CLIMB? WTF)

(I love EV training with PokeRus, the Power Lens, and fighting Golducks. :D)

LOL nvm, I now got +42 Speed XD

 

[mattman324]

I don't EV train, but a few days ago, in FR, I was doing my Blastoise powerhouse challenge with a Naive Blastoise, and got through Lt. Surge's gym (Electric types = Speed EVs up the arse.) without leveling up until I defeated Raichu.

IIRC, it was +5

 

[Yusshin]

+12DEF on a Noctowl in Pearl.

 

[Halcyon]

+16 Speed on my beloved Shiny Horsea! :D
Yay to Magikarp fishermen!

 

[batmon]

I never do EV training, but IIRC it was +8 in Special Attack when I was training my old Raichu against Spindia. I almost had a heart attack.

 

[Enigma]

I think I got like, +10 or 12 on my Ho-oh once when I used to train it all the time.

 

[LyokoGirl5000]

I got +21 for HP on a Blissey once.