I've always wondered that myself. The only thing I can think is that once they get old and have a particular look to thier antlers, then it becomes easy, but to tell a 1 1/2 old in his next year I think has to be impossible, just from the rack. That said, I do believe I have for the 1st time ever seen a buck on consecutive years. Last year I saw a scrappy little 6, that was piebald slightly around his sides. This year I saw a beauty 8, perfect symmetry, with those same markings. I am just about positive its the same buck.