If your season has an opening day before the 1st week of Oct. you stand a good shot at taking a mature buck. The reason is because it allows you to catch a mature buck while he's still on a predictable feeding pattern. Usually, for my area, after the first week of Oct. the bucks break up out of their bachelor groups and go to their core areas. They remain there until around Oct. 17th when they start coming put before dark to check on does around a food source. One other thing I've noticed is that the biggest bucks usually hang by themselves, not in bachelor groups. They do their own thing. Sometimes you can catch one early but they are more difficult to pattern.