Poss Hets

When you are using poss hets to breed (50% and 66%) for example 66% het albino to a known 100% het albino. how many breeding season will you continue to breed when you are not hitting the odds(getting the albino you were looking for).

I've heard that most would try them out for two season's, I'm going to try my girl's out for two season's also if they don't prove out the first time.