Here's an analogy I use for dogs and biting. Say your dog is a person and the stock is Mike Tyson. Mike is in a good mood and pretty amiable in this. You tell your buddy to go and ask him to leave. The bar is closing and no one can stay any longer. At the end of the day, he's leaving whether he likes it or not. Hopefully it's as easy as that one ask. But just in case, I'm not going to tie my buddies arms behind his back before he asks Mike to leave. Then he'll have no way to defend himself and will probably back down at the first sign of confrontation. This is exactly how dogs biting works. I don't want my dog to pick a fight but I also don't want them to back down from one. And one of the fastest way to shake a dogs confidence is putting them in unwinnable situations then punishing them for not winning. I'll let a dog bite if it has to. No more then it has to certainly but the dog has to know I won't hamstring him when push comes to shove. At the beginning I've found that can mean the dog bites more often then it needs to. Despite that, I'll let the dog work through when to and when not to bite on it's own as much as possible. I'll always discourage nonsense bites, like a hamstring or a belly. But I'll normally let them take the head and take it more then they have to initially. It's one of the reasons why I start my dogs a bit younger and strictly on sheep. That way I can mostly control things to where no animals are getting truly hurt. With that said, there are times where dogs can't just work through those growing pains. That is slightly tougher to describe. The best I can desribe is that I'll let a dog bite out of anxiety or a desire to learn and try BUT I won't allow a dog to bite out of its desire to harm my stock or flatly disobey me. That's true in every aspect of training, stockmanship and partnership is first. Yet if they need to work through some mental pressure, we will do that. What I'm left with is normally as confident a dog as he can be. They know that they have the tools they need to get the job done. Now there is a caviat to letting a dog bite. It should only be used as to improve the situation. They shouldn't bite so that it scatters stock and they shouldn't harass stock that is already moving. That knowledge takes time. I have taken a full year to help my dog know the difference but the time was well worth it. Now let me leave you with one last bit of wisdom. Dogs power is almost always born in them; whatever that level is. Confidence helps that power flourish. Insecurity can kill their power. Effective biting can help confidence but biting is NOT power. Power is the ability to move any stock, regardless of biting.