Bucks tend to eat like crazy during the weeks before the rut. Once heavily into the world of pheromones and swollen necks, they don't eat; also, they drink much less water. Thus, they have a heckuva fat buildup at the beginning of the rut. This tends to curtail daytime activity, just as you would slow down were you wearing a down jacket on a hot day.
SFAIK, this is part of why the larger bucks and the true trophy bucks are more active later into the season. Cooler or colder weather, and that down jacket doesn't slow them down as much.
By and large, the best deer for eating are found during the earlier part of the season; the best trophies are taken later.
But no deer absolutely always "goes by Art's book". Which is what makes it so much fun.
, Art