Excellent points, Dick. The evaluation of a 'hump' as bad, good or indifferent is troublesome for me. If there is a significant hump in a young fish, I am never sure if it is an indicator of a stumpy adult, or if it is the effect of lots of food being stored as reserves due to the fish being raised in cooler water. JR was making a point about this in a conversation at the NKF harvest when something came up and I was not able to discuss it further with him.
When I get to see photos of very large (long) koi when they were tosai, it is typical that they are long and a bit on the thin side. All the nutrition is going into growing longer. The same fish as nisai coming out of the mud can be fatter than could have been imagined, with a bulky shoulder, but not not necessarily a 'hump'.
You may recall "Vamp", the Marusada Showa I got a few years ago. (There's a thread on this board some place.) She had a huge hump as nisai. There is no sign of it today. She is a streamlined fish with a deep magoi-type body, and the look of being a bit underfed because she does not hold eggs or fat on her sides. I suspect she would re-develop a hump if in a mudpond for a full season.
Altogether, very difficult for me to 'read the future' of such fish. I kinda have the sense that if the head proportions are large, the 'hump' is not so much of a concern on one straight out of the mud, that they may well grow out of it; but if the head proportions are average or 'pointy', the 'hump' is more of a concern.
So..... how about correcting my confusion?