You keep them all or place them into good hands and surely a pick of the litter will pop up lol. Jack also bred a family, linebred & inbred on a few dogs who were his "flagship" animals and consistently threw what he wanted out of his animals. You won't know if your dogs will bite hard or not. Some lines are bred around mouth and even that don't guarantee that your pup will bite. Good health, good exercise and one day he will show you how hard he bites. Keep them all and then you will know.