To me it is usually a calf that has some growth to it, a little more frame and less condition. I don't mean height, just a calf that is not a pud. A little looser made as a calf, the kind they always seem to say "oh he'll make a good fat steer". They tend to look greener than the jackpot calves.
This calf was a good feeder, had a stretch of 30 days where he was gaining 4.7 pounds a day on 27 pounds of feed and free choice hay.
He always had an appetite and never seemed to slow down, he weighed 720 the first part of November and 1430 in the picture at the fair in early July.
They don't look finished and big gutted until they should be finished and big gutted.