A Border Collie is just that -a breed of dog - It does not become a SHEEPDOG until it is trained to work stock proficiently.
"Money will buy you a pretty good dog, but it won't buy the wag of his tail."
--Josh Billings
A Sheepdog when trained to any standard may or may not work in a proficient way for its new handler, there can never be any guarantees on compatibility due to the diversity of human and canine temperaments.
A trained sheepdog needs to understand, trust and respect any new handler before working proficiently for them.
If there is a problem, it will almost always be coming from the handler and not the dog.
