By the odds of 1:13 do they mean by I have to hatch only 14 pokemon and I'll get finally one?
Say like you have a nature that doesn't boost attack and characteristic trait that is often dozes off but then you have 31 IVs in all stats and you EV train 252 in the attack stat. Will you still get max attack IVs?
Not necessarily, just because those are the odds doesn't mean you'll get one in the amounts of times the odds are, but yes, hypothetically you should get one after 14 eggs.
Oh, hey, to jpp8's post, there is a MUCH easier way to get a perfect Ditto. In fact, I have one with me at the moment. Read
The Smogon RNG Abuse Thread if you want one yourself =p.
Yeah.... you will still have 31 IVs in attack. IVs
never change after you receive/catch the Pokémon. You will not, however, have the maximum attack stat. In order to get max attack, you will need to get an attack-boosting nature, like Adamant, Brave, Lonely or Naughty (preferably Adamant).
Perfect IV'd Pokés are
VERY valuable (and mostly hacked) right now, but with the method above ^, they are becoming more commonplace.