I recently decided to start making a competitive 5th gen team, so I started hatching Deino eggs to make a competitive Hydreigon. I wanted it to have Dark Pulse, but it's an egg move only and requires a 4th gen TM. I taught Dark Pulse to an Arbok in SS and sent it up, and then I caught a male and female Deino in Victory Road.
After hatching for a while, I realized that the hatchlings didn't have Dark Pulse. Sure enough, the Arbok from SS was female, and TM egg moves are only passed down by males.
*facepalm*
So I found a male Arbok in Diamond and transferred it up, proceeding to hatch until I found a Modest female so I could Everstone for a 50% chance of passing down the nature. But since this Deino was a hatchling, it would level up rather rapidly in Day Care - to avoid paying exorbitant sums, I leveled it up to about 25.
I then hatched several batches of 5 each (with Volcarona to Flame Body and Fly to Skyarrow Bridge) until I got a Mischievous one. I trained it to level 20 and checked Serebii's IV calculator, and it had a 31 in Sp. Attack! I spent about 5 hours on the Battle Subway to get the points for a Power Lens, but I finally got one so I could pass on Sp. Atk.
After hatching a few more batches, I realized that the new hatchlings weren't getting Mischievous as much as I would expect. Could more than half of these randomly have 31 IVs in other stats?
"lol," no. I forgot to factor in the EVs when calculating the parent's IV, and the mother's Mischievous was actually a 26, haha. I was passing down imperfect stats!! :cer_laugh:
So I took off the Power Lens and hatched many more batches, until finally I had a couple more Mischievous ones. I trained them each to level 25 and checked the online IV calculator again, and I finally managed to get one with a perfect Sp. Attack stat. I used that to replace the father Arbok.
Only after that did I learn that you can check for perfect IVs in the Battle Subway!! *facepalm* I started checking every new hatchling there, looking for one that was Modest and had another flawless stat in addition to Sp. Attack.
I eventually found a female with flawless Speed, and another couple of hours in the Battle Subway got me the Power Anklet to guarantee a perfect Speed stat. Now I could guarantee eggs with two perfect IVs.
...or so I thought. It turns out that you can only pass down one stat with a Power Item, so after a few more batches I swapped the Power Anklet for the Everstone again.
After a couple of days I got one with flawless HP. Since HP is less likely to pass down than Sp. Attack or Speed, I went through the Battle Subway again and managed to get the Power Weight. This took an incredible amount of time because I kept losing due to my not having EV-trained Pokemon, which is the reason I'm going through this whole process!! "lol" once I get my competitively viable Deino, I won't need the Battle Subway anymore for the Power Items. :pink_laugh:
So now I had guaranteed flawless HP, a 33% chance of flawless Sp. Attack (one flawless parent), and a 33% chance of flawless Speed.
I hatched maybe a hundred more eggs, but I noticed that the hatchlings didn't have Dark Pulse anymore. I had left the father in Day Care so long that it had overwritten the move!! "lol" so I had to take one of the flawed hatchlings that I kept, train it to level 25, and then hatch for the flawless HP again. I finally got it and kept replacing with better Deinos until I reached where I am now: a male with 31s in HP, Defense, and Sp. Attack and a female with 31s in HP, Sp. Attack, and Speed. HP is guaranteed to be flawless and there's a 50% chance of a Modest nature, with a 14% chance of flawless Defense, 33% chance of flawless Sp. Attack and a 20% chance for flawless Speed. I'm probably going to keep hatching until I get one with 4 flawlesses, although if it's not Modest I can put it in Day Care to improve my chances of getting a hatchling with flawlesses in 5 stats.
What does all this have to do with shinies? Well, I haven't been counting eggs, but given all I've done there have probably been at least 500. My chances of getting an outstanding competitive Deino are pretty slim, so hopefully I'll get a shiny in the meantime!
And if I do, it's guaranteed to have a 31 IV in HP!! :cer_laugh: