Why is raising a pikachu different for me in fire red and platinum?

Question

I like raising pikachu a lot, I caught one in the abandoned power plant in kanto and I've raised it to lv 78 which is pretty good for the elite 4 but what confuses me is that a pikachu I raised as my main Pokemon in platinum had good defense and excellent offense (due to light ball) and even when I used it at lv 62 against the elite 4 and Cynthia it was good defensively and offensively and my star player, it took two extremeSpeeds from lucario lv 60 ps a previous battle recoil damage from volt tackle and still survived at 1 Hp and also won the match for me. Now the problem in fire red is that why is it so defensively poor, it took one sky uppercut from hitmonchamp lv 65 and its Hp got so low (lowest yellow point) although in both the games I had maximised all stats with zinc, iron etc. So why is pikachu so poor to battle Pokemon which are even 12, 11 levels weaker than it? This problem is only in fire red, when it was Pokemon platinum I had no complains, I thought it was all up to the stats

Comments

What's an iv?

Answer 1

The reasons for your two Pokemon being different is EVs, IVs, and natures. Effort Values.

Effort values (Japanese: 努力値 effort values), abbreviated EVs, are attributes which give bonuses to an individual Pokémon's stats and improve differently depending which Pokémon they defeat. Officially, they have been referred to as 基礎ポイント base points in Japanese since Pokémon Gold and Silver and as base stats in English since Pokémon FireRed and LeafGreen.

EVs are points that increase your stats that your Pokemon gain by defeating other Pokemon. Different Pokemon give out different EVs, so a Pokemon that defeat a lot of Pokemon that give out Defense EVs, it will have a better Defense stat. As far as I know, EVs cannot be changed or reset in games before Pokemon X and Y.

Individual values (Japanese: 個体値 individual values), abbreviated IVs, and sometimes referred to as determinant values (DVs) in the context of Generations I and II, are the Pokémon equivalent of genes. They are instrumental in determining the stats of a Pokémon, being responsible for the large variation in stats among untrained Pokémon of the same species.

IVs are basically EVs that are determined when a Pokemon is obtained. IVs cannot be changed in any legitimate way

A Pokémon's Nature usually affects the growth rate of two of its stats, ultimately increasing one of its non-HP stats (Attack, Defense, Special Attack, Special Defense, or Speed) by 10% and decreasing another by 10%.

Natures change how the stats of a Pokemon grow. For example, a Pokemon with the Jolly Nature would have a Speed stat that is increased by 10%, but a Special Attack stat that is decreased by 10%. Like IVs, Natures cannot be changed once a Pokemon is obtained.

In the case of your Pikachu in FireRed, it probably has low Defense EVs and/or IVs, and/or a Nature that lowers Defense/Special Defense.

Sources: This, this, and this

Comments

so im going to play pokemon platinum from the start and im going to catch a pikachu and train it hard
so how can i make sure it has the exact IV's and stuff etc for good def and sp. def

---

To get the IVs and Natures all require a lot of breeding and hard work. (Unless you have extremely good luck.) Without breeding, it's very hard to get the IVs and Nature that you want. If you really want to breed for IVs and Nature, I suggest that you look up a guide instead of talking to me about it. I've never bred for IVs or Nature so I don't know how to do it well.
As for EVs, they depend on the Pokemon your Pikachu defeats, so if you want to get good Defense and Special Defense EVs, you need to defeat Pokemon that give out Defense and Special Defense EVs. You can find a list of what Pokemon give out what type of EVs here http://bulbapedia.bulbagarden.net/wiki/List_of_Pok%C3%A9mon_by_effort_value_yield

I haven't EV trained either so there's a chance that I got something wrong.