I just used this evaluation tool a few weeks ago when culling a few cockerels (looking for the best one) and it was great. I was so focused, however, on getting the right 'feel' of the body (girth sizes, angles, etc) according to the tool, that I completely forgot to check over the easier stuff... I had chosen my best keeper cockerel and the next day I realized he was cross-beaked! I had never seen it before on him and it wasnt a bad cross-beak but certainly not a cockerel worth breeding. I really have no clue how it happened as I hatched all the cockerels and have never noticed the cross beak (and I do a lot of staring when they are tiny). So perhaps it was some sort of injury later in life- anyway, the point is don't forget the obvious stuff!