The drift calculations, as you point out, show more is better. And it's tough, because ensuring just a given allele is preserved takes tons of plants. It's far worse given that we want entire ensembles of alleles!
Originally Posted by Yard dog
As you can see from the above the more the better, now if for example you took an example like Tomhills haze were he stated 5% were the great ones giving you 5/100 or 1/20, you need 20 to make sure you capture that 1.
Your example is much trickier than this. You cannot
count on getting a great thh with just 20 plants. Any given 20 plant grow, with 1/20 being 'great', has a 36% chance of not showing that rare 'great'! I'm not sure about you, but I think making sure you capture that greatness would mean having, what, a 90, 95, or maybe even 99% chance of finding the 1/20 type?
These levels of certainty require 45, 59, and 90 plants, respectively. But maybe we should account for females? Then we'd need roughly double the plants to be 'sure' to capture the 'great' type. The math is simple, but the implications are challenging!