I think there is really an easy answer to all this. If you have a pack of dogs you use for hunting or trialing and you run your pups with and without the pack, you will know when they are ready to "run with the big dogs". If you run your pup with the pack (or at a trial) and he gets left behind, cheats, or runs with his head up, he's not ready. If you keep running him in that setting you can ruin him. I can think of one virtue to taking them early (in moderation) though. I tried to take some of my dad's 5-6 yr olds that had never been trialed. They were good dogs, but all the strange dogs, people, leashing and unleashing just freaked them out. They were used to us opening the box and running for half a day with the same people and the same dogs. When I started trialing, my pups were 8 months old. I took them a little but tried not to overdo it. Just remember, you are trying to develop the dog, and he may not peak 'til he's 3 yrs old. Give him the best chance you can. If you don't have a pack to run him with, enter him in a trial every 2 or 3 months til you think he's ready. I've got an 8-month old puppy that I will probably take to a LP trial in a couple of weeks. I'll probably stake him out and maybe show him on the bench, but I won't enter him in the hunt because I don't want him picking up any LP habits. He probably won't run LP 'til he's at least 2, but I'd enter him in a PP trial now. (LP is my only choice close to home). My 2 cents. Take it or leave it.