Hello everyone! So you'd like to breed and be the best? Well I'd like to make a contribution by making a guide to easy breeding for competitive purposes in Pokémon X & Y. This may help you!
SHINY HUNTING MASUDA METHOD:
While the standard encounter rate for a Shiny Pokémon (either in the wild or by breeding) is 1/8192, the Masuda method multiplies this rate by 5 (to 5/8192 or about 1/1638) in Generation IV and by 6 (to 3/4096 or about 1/1365) in Generation V. It occurs whenever Pokémon of differing real-world geographical origin are bred.
So a foreign Ditto is a treasure for Shiny Hunters...
First off, what do you need to know:
Natures: The nature a Pokémon has either be neutral or provide a boost to a stat while hindering another one. For example, Adamant nature gives the Pokémon a boost in Attack, but it hinders its SpecialAttack, likewise Modest boosts SP.Atk, while hindering Attack. See table below:
Egg Groups: Pokémon in the same egg group can breed, a Pokémon may have more than one group. Check Serebii to know the specific Egg group of a Pokémon.
Egg Moves: Some moves can't be learned by leveling up or by TM's HM's nor Move tutors, but can be passed down by a parent (Check Serebii for the moves a Pokémon can inherit); the moves a newly hatch pokémon will have are as follows:
1)Moves they'd learn at lv.1.
2)Moves the parents learned by leveling up (that the first state can learn)
3)Any TM's or HM's the father knows. (Only up to Gen V)
4)The EGG MOVES the father knows.
Individual Values: Every Pokémon has an IV of 0-31 in every stat, 0 being awful and 31 being the best, these IV's determine how well a pokémon will have an stat. For example, a Timid Jolteon with 0 IV's will be able to obtain 291 in Speed, while one with 31 will be able to obtain 394. Pretty important difference... You can check your IV's in the Pokémon Center of Kiloude City.
Things that could benefit/ease your work:
*Power Items: Since Heart Gold/ Soul Silver, if a parent holds a Power Item it will pass down the IV's in the stats the Power item boost (for example, Power anklet-> Speed)
*Good Natured/IV's Ditto: If you have a Ditto you'll have an easier time passing down natures and IV's since Ditto's can mate with all the pokémon (who can breed)
*Destiny Knot: This item, when hold by a parent, will make that 5 random IV's from either parent are passed down.
*Everstone: When a Pokémon holds an everstone, the child will inherit its nature.
Things to consider:
-Pokémon with the ability "Flame Body" when in party, will reduce the hatch steps for an egg to the half...
-Pokémon caught in the Friend Safari will have 2 stats with max IV's or more. (Agidyne has a friend safari with Dittos, so this will come in handy)
-When mating with a Pokémon in the same egg group, the child will have 80% of probability of getting the ability of the mother (with non-hidden abilities) hidden abilities have 60% of being passed down.
What's known as chain breeding is to progressively improve the Pokémon offspring for example:
Let's say I want a Jolteon, so I catch a normal Eevee, but I have several Ditto with good Natures and IV's, so the chain starts:
1)Eevee+Ditto(31 IV's in Sp.Atk and Speed) I give the Ditto the Destiny Knot to hold, so the offspring will be an Eevee(2) with max IV's in Sp.Atk and Speed, impressive, but not enough.
2)Then I breed Eevee(2) with another Ditto (who has Timid nature) so I give the everstone to Ditto and the Destiny Knot to Eevee, know Eevee(3) has 2 maxed out stats and a good nature.
You could stop here and have a great pokémon, since Jolteon is a fast special sweeper, meaning he doesn't need defences or physical attack, just to hit hard and fast with special moves, which Eevee(3) can do, you just need to proceed and EV train it in super training...
If you want a Pokémon with more perfect IV's you'll just need to keep the breeding chains until you get your desired Pokémon.
Also, if you want a Pokémon with 3+ perfect IV's, get the right natures first...
*Catch a lot of Dittos in the Friend Safari.
*It's useful to rename your Dittos to their high stats, for example Speed-Sp.Def, or so, so you don't need to constantly go and check their IV's. You can also mark the status symbols if you don't want to rename your Pokémon.
*Any doubts, feel free to ask me.