Do emerald berries that lower EVs also lower stats if your pokemon eats enough?

Do the berries that lower 10 EVs each also lower your stat points?

For example, let's say a lv 90 Gyarados eats 11 Kelpsy berries to lower its attack EVs. Will its attack actually lower down(assuming it had some EVs on attack) iF it doesn't, is it possible to keep "resetting" your pokemon's EV's then retraining them back again?

3 Answers

In Generations I through IV, the game applies EV changes during level up. This is why if you had a clean level 100 Pokémon and wanted to EV train it, you had to utilize the Box Trick. I'm fairly sure that because of this, you wouldn't experience a stat drop upon using the EV berries unless you used the Box Trick (I'm not certain).

However, in Generation V, EVs are applied directly after battle, so you could cause your level 100 Pokémon's stats to go up and down.

3

EVs directly correspond to an increase in pokemon stats. If eating the berry reduces the EV by enough to cause a drop in stats, it will be either reflected immediately, or during the next level up (when EVs are normally distributed, if applicable) -- I don't know for sure.

However, I can say for certain that eating berries and then retraining a pokemon's EVs, will never cause you to overstep the hardcap limit on EVs, either for an individual stat or total EV increase.

1

To expand a bit on Kevin Y's explanation:

EVs affect your stat directly. Every 4 EVs will increase the stat by one. Therefore if you feed 11 berries to something to lower its attack EVs, its attack will decrease by anywhere from 63 to 0, depending on how many EVs it had and what level it was, once it levels up.

Until it levels up (or using the Box Trick as Kevin Y said), it will keep its current stats. The same is true when gaining EVs. You don't see the stat boost until the Pokemon levels up. This is why it's very difficult or impossible to EV train level 100 Pokemon.