Wait wait, I don't trade eggs between games to check shininess, I check the PID of a spread (in binary) with all the mids using Word and then trade the egg in the .sav with the "perfect match".
Anyway, I bred my calm chansey when I had 200 sav files and now I have around 400 sav files... Geren told me he bred all his emerald shinies with just 128 sav files.