If you breed a pair of hets from now until infinity and average everything out, I can guarantee you'll get 1/4 homozygous :-) Other than that, you're on your own. For example, if you over three years you had three clutches of 6 eggs each, then your odds of NOT getting a pied would be:

[(.75)^6]^3=.0056, so after three years you have a .56% chance of not having produced a Pied. If you're that unlucky, I'd stay away from any gambling whatsoever.

JonV