Smaller Mac`s hold in the deep water for protection during the day (as do ling). When the light starts to go they move into the shallows to feed on smaller fish that live in closer to the banks, ie. small mouth bass, chubs, white suckers etc.. That is the reason that you catch the smaller ones at night. The ones in the morning are ones that are moving to the depths for the day.
The big boys on the other hand just go were the feed is when they are hungry. They don`t have to feed on smaller prey so they can stay deep or go shallow, what ever the need is at the time. I have caught several decent fish very close to the shore in the fall after the water temperature has equalized and the bigger ones put on the fall feed bag.
I don`t clam to be a fish biologist, just my thoughts on it.
