RE: What's the oldest deer you've taken?
The DOW did a study involving over 1000 wildlife biologists aging deer based on the jaw. All the jaw bones came from deer of known age ranging from fawn on beyond 10 years old. The biologists were just to age the deer. The conclusions of the study were that beyond 3.5 the group as a whole was incorrect much more often than they were correct. Because of this study, deer checked by biologists at checking stations for study purposes are listed as fawn, 1.5, 2.5, 3.5 and over.
Obviously, if you know the deer personally (for lack of a better term) then you can age it based on that, but you cannot do it from the jaw like so many will tell you.
You are right Greg, it is a highly educated guess for some and they will probably get within a year, but if you want to know for sure you have toscope the teeth or weigh the lense.
I only know any of this because I was educated this year by a wildlife biologist neighbor of mine. I was way more ignorant than I thought I was prior to this year. It has been an amazing wake up learning more about this subject.