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100% het x WT (normal) = each egg has a 50% chance of hatching a 100% het
100% het x 100% het = each egg has a 25% chance of hatching a WT, 50% chance of hatching a 100% het, and 25% chance of hatching an albino
Since albinos are visually apparent, we can then remove them from any het or WT math. That takes 25% of the statistical probability out for the discussion of hets. You can then look at the remainder as being three chances instead of four among the remaining 75%. Two chances per egg of hatching a normal-looking 100% het and one chance per egg of hatching a normal-looking non-het (aka wild type / WT / normal). Since you cannot visually distinguish between these hets and non-hets, these are then regarded as 2/3rds hets (but hets are technically all or nothing in fact). Some people round down from 66.6 (repeating after division of 2/3) to 66% het and some people (like myself) round up (since it is at or over 5 for the next whole number) to 67% het when assigning the label for these normal-looking hatchlings. In summary, normal-looking offspring from het to het breeding for a simple recessive trait are labeled at 66% or 67% hets.
If there is an albino parent, all normal-looking offspring are 100% hets. If there is an albino parent and a het parent, an egg has a 50% chance of hatching out an albino instead of just a het. If both parents are albinos (with the same locus, as we assume throughout for this particular example), then 100% of the offspring will be albinos.
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