thank you for the link, the article post was great.
As I read the post I thought about a three farm team that mentioned raising buckeyes where each farm took on one different weak point in the three flocks. I as a newbie can't comprehend culling for so many detractors, failures or weak features. I can see that my progress might proceed at a faster rate if I only raised from 2% of my hens but I might also perpetuate a very weak gene that was hidden, because of my inexperience.
You're not going to be able to see everything all at once. It almost sneaks up on you. You notice one or two things more often when you're first starting. Then as you raise more birds from hatch to maturity, you start seeing other things and you make correlations with earlier observations. And you start seeing things sooner than you did before. That's the part of getting familiar with your group of birds. It seems intimidating at first, but things start slipping into place and you have those *aha!* moments and wonder why in the world you didn't see something sooner.
I read that post about the Dels, what they did not spell out is that this was the amount of time it took to reach where they are now. It is easy to read that post talking about the different birds and how they turned out, but people don't always remember that chickens aren't ready to breed and hatch from every couple of months. It takes about a year, sometimes more, to get each group hatched and matured enough to see the results of the genetic pairings, and then be able to breed, hatch, and raise again to see further improvements or more flaws. So people shouldn't beat themselves up when they aren't getting things accomplished quickly. The postings and photos make it seem fast, but it really isn't.
And neopolitaincrazy is so right - you'll be going along fine and something will pop up out of thin air that you have not seen in your flock before. I've seen the breeder we obtained our original birds from telling people "my birds don't have the problem". Their birds may not have that problem they were talking about, but it is in the genes because the original birds we got from them have those flaws. And then the offspring from our original birds has had some flaws come up that their parents didn't have. And we only have one breed, so we know that these issues are not coming up from any crossbreeding. They are just there and when the right combo of genetic material meets, something weird shows up. But it's not the end of the world. When these things pop up. As you get acquainted with your flock, you learn which things you need to emphasize, which things you need to fix soon, and which things can sit in the corner and simmer a while before you need to take any drastic action.