If it is shiny it will be due to luck. I do not RNG. I do not have the time or the patience right now to learn. What I do is hatch around 45 to 60 eggs to get the I.V.'s I want and the natures prefered. With a flawless ditto and a flawless gengar it should not take me long to get a gastly with the stats and natures I want for battle. I am making a team of pokemon I could use in a tourney if I choose because they are all going to have me as the trainer and they will all be hatched by me so I will know beyond a shadow of a doubt that they are legit/legal.