Looking at the chest depth to front leg length ratio, I'm going with 3 1/2. Now let me see him in late October and I may change my mind!
Exactly!
I think there's high probability this buck may be 4 1/2, but little conviction for any older than 4 1/2 (at the moment)
But to "go by the book of BSK", 3 1/2 or older, 3 1/2 being the oldest age of high conviction.
Or put another way, the stated age of 3 1/2 is the age for which it's very unlikely he could be any younger than, while not ruling out he may be older.
Show the same pose in late October, good chance the guess goes to 4 1/2 or older.