Frame score and mature weight are influenced by the environment as is BW. A FS 6 animal wit hthe exact genetics in PA or NY is going to be less in SC and a FS 7 in MT is going to be smaller in PA. It is a function of latitude and longitude. The folks in the south or SE USA do not "like" smaller frame cattle, they are what the average feed animal is due to environment. I see a huge difference in heights at weaning, yearling and mature size due to available and quality of pastures and hay, if in a drought and I want to hold a few. The dollars are for the market calves that are nearer weaning and have decent weaning heights. The interest in bull buyers is in the yearling heights and nobody seems too motivated on the mature heights except folks like me who do not want goliaths grazing in the pastures. The most variable is the YH. The WH and MH will be similar or closer.