First, let me emphasize that field-judging age is an art and not a science. Although I've been perfecting my skills for many years, I still only get 4 out of 5 buck ages right. Let me also emphasize that deer from different geographic regions will have different body conformation characteristics by age. All of the following pictures (except one) are TN bucks.

Second, when field-judging buck age, always, always, ALWAYS ignore the antlers. I've seen 80-class yearlings and 80-class 5 1/2 year-old bucks. Antlers will fool you more often than any other feature. Just look at the body.

Yearling (1 1/2 year-old) bucks:

Yearling bucks are best described as "does with antlers." They have the gracile necks of does, and the long bodies of does. Some yearling bucks will have body musculature greater than does, but the almost always have legs that look very long for the thickness of the body.

In fact, at least for me, the two most important and consistent body characteristics to look at are the length of the legs in comparison to the vertical thickness of the body, and the juncture of the neck with the front of the shoulders. Those two characteristics seem to be the best for judging TN bucks.

Notice in the following pictures how narrow the bucks' necks are, even where they join the shoulder. A very clear distinction between the base of the neck and the beginning of the shoulders exists. Also notice how long these bucks' legs look in comparison to the vertical height/thickness of the shoulder and body trunk. Viewed from the front, yearling buck are also very doe-like in how narrow their bodies are from side to side.

"Know where you stand, and stand there" --Jesuit Father Daniel Berrigan

"There is no reasoning someone out of a position he has not reasoned himself into." --Clive James