Pot luck, the amount of not so good pups out of every litter, no matter how good the parents, is, to my mind, enough proof that worker to worker has no real advantage over litters that aren't bred from worker to worker. Hare coursing whippet champions have been bred from dogs that have never seen a hare in their lives, and racing greyhounds and horses follow a similar patern. As long as they've got the right bloodline they'll be bred from. And in all livestock breeding, breed enough and you'll get some good ones. Edited to add, I just realised I'm in the terrier section! lol, but you get my