I feel pretty confident in aging deer in three catagories if I can see them broadside with their heads up. A 1.5 year old looks like a doe with antlers. From 2.5 years to 3.5 years is an educated guess depending on the deer. The last category is 4.5 or older. That’s about all I will commit to. I watched a deer aging video years ago where it showed you a buck and paused while you made up your mind, then told you how old the deer was. I did very well on these known age bucks. Having said that, it varies with what part of the world that buck is in, even in my state it’s hard to age our different bucks. Each region has different body weights from the smaller Hill Country deer, the larger S. TX deer, and the bigger bodied deer next to OK. I don’t think you can pin it down to the year each time. I do believe that bucks can be aged well enough to shoot the buck you need/want to take.