I think 1.5
Here is a pic of the two bucks I shot last year. I had them aged when I registered them 3.5 on the left, and 5.5 on the right.
1. Look at the pronounced curve in the snout below the eyes sockets. As a buck ages this will get a more filled out and look like a straight line.
2. The white hair around the eyes. By age 3 it starts to look more filtered into the face
3. white hair on the sides of the nose. by age 3 is usually filtering into the top of the snout. By age 6, the snout is very white.
4. High brisket line
5. rump has little developement. The 5.5yr has a HUGE Azz on that boy.
6 muscle tone of the mid section of the rear legs. By 3-4 years the mid section of the hind legs will have a defined muscle tone instead of it looking like a stick poking down from the hind quarter. By 5 6 years it looks like an additional muscle mass added beneath the hind quarter.
Well, agree or disagree, this is what I look when guessing