i'm going to disagree with that. there is a lot of luck in hunting. either you see a deer or you don't. its more important to practice shooting before you go hunting deer. know the effective range of your rifle and whats beyond that. learn to judge distances. i could understand knowing the species of deer so you dont shoot a muley during whitetail season or visa versa. you need to knowthe distances that your capable of shooting accuratly. this guy doesnt need to know the genetics and temperment of deer during the rut he needs to know whether or not he can shoot that far if the deer walks out and confident with his rifle and his accuracy. the only way to do that is practice, practice, practice.