Genetics and diet are true players. Thats also why even i admit when there is a drought you can see the effects of poor dieting in the deer. Growth isnt as good as it is in the banner years. Age also plays a role yet probably the least in the three factors. But how he lived will eventually increase its influence as time progress's. Got to keep in mind the older the deer gets the more worn his body becomes. The more nutrients his body requires for energy, possible wound healing, and other factors. All that just to keep up and ahead of predators, dominance, and alive. At a certain point the body will primary take the nutrients to where the body needs it and not so much where the rack comes into play.