I'd just like to say that for anybody who is looking at this post for answers, the answer above is incorrect. With two 6IV parents, the chances are 1/32 of a perfect 6IV offspring not 6/32. Also, there is no way to guarantee a perfect 6IV offspring, using Power Items does not guarantee nor does it increase the chance of a 6IV offspring, it only guarantees the selected IV will be passed down, with 6IV parents the chance is still 1/32 even with the Power Item.