Let's take the Pied gene as an example
Pied X Normal = 100% Het All offsprings are normal looking and all carry the pied gene.
If you pair a 100% Het Pied to 100% Het Pied you will have 25% chance to produce a Pied (chances per egg) , you will also produce het pied and normal, however since you cannot tell apart the normal from the hets they are all considered 66% possible hets.
If you pair a 100% Het to a normal, you will produce normal and hets however this time since again you cannot tell them apart they will be considered 50% possible hets.
Hope that was simple enough.
With your example if you breed a YB 100% Het Pied to a Pied you will hatch YB Pied, Pied, YB Het Pied, Het Pied.
If you breed a YB 50% Het Pied the results might be the same as above IF and only if your YB proves out to be Het Pied. depending on the odds it might take few season to prove a possible het out.
I just hatched this clutch from Leopard CG 100% Het Hypo Possible Het Pied, obviously in this case the male proved and is indeed Het Pied
http://ball-pythons.net/forums/showt...ow-Pied-anyone