Single post in Your Guide to 90%+ Breeding Pairs

Hi there, Sorry if this has already been answered somewhere and I missed it. I'm trying to iv hunt snichu. I have a vilechu and a pikachu with okay ivs in the daycare. They are breeding fairly well, I have a lot of sneasel and pichu eggs - and zero snichu eggs. Any ideas on what I'm missing? Do both parents need to be vilechu? What can I do to boost the output of snichu eggs? Thanks for your time.