Evaluating a young dogs "bottom"

I for one do not like a ton of bottom or let me re-phrase it I admire the hell out of it but it is not an option for me to have in my own dogs and have always had to trade off dogs that i have had that have had good long solid bottom on a hog. I think "recognizing" signs in a young pup you can start to see it at 5-6 months, but thats not going to be on a hog but other things. We have a young dog we bought and raiseda s a pup that impresses me at 5 months which I do not expect or care if they show intrest at this age but this pup did go to hog pen, and stay at the pen running around until get too hot and would stop go get cool and go back without another dog around for long periods of time until I came and made him stop. His focus was and still there that usually not in a pup of that age. attention spans on dogs this age are usually short, very short. However i believe with conditioning and letting this dog go and by trackining to him he will be a dog that will and can stay with a hog much longer than I am prepared to go. He will be conditioned in another direction.
If the dog is born with it, its there, its just knowing its there, and not "hoping its there" I guess. I don't breed for it like some folks do, so maybe not the answer you were asking for, but still I agree within 18 months to that question. Although I have known a couple dogs around 4-5 years of age begin to become condition when owners changed that they always follow the dog with the tracking system and the dogs could keep going further, the dogs conditioned into being rangier and working a track further and putting a hog at the end. where as owner before would not follow the dog, could not hear a dog that far out and after getting lost a few times I believe caused the dogs not to range or work as far.