You might occasionally run into 33% or 25% chance hets. These where never well accepted terms and now that hets in general are more reasonable don't usually even get mentioned. They are the respective offspring of an untested 66% or 50% chance het to a normal. If you had a large number of such offspring from a large number of different 66% or 50% chance hets you would expect about 33% or 25% respectively to be hets. But for each clutch they are either near 0% or 50% depending on if the possible het parent hit their chance or not. The uncertainty of even having a chance due to this extra generation of removal from a know het is what makes naming 33% and 25% chance hets controversial.

I produced 5 pieds this last year from two 25% chance het pied girls bred to a 66% chance het male. However, since pied has co-dominant tendencies this wasn't nearly as lucky as it sounds (I would have been very surprised if any of these well markered possible hets hadn't proven).