I want to ask what is meant by bloodline here? Is it the pedigree of a registered champion (for example, there are excellent non-racing dogs) or is it the pedigree of an American or English dog?
If it is just the kind of login champion straight children straight girls are generally kennel bred, double blood is at most parents are login champions. Blood is basically a straight grandchild or a straight grandchild, and a lot of family members talk about double blood in order to create a gimmick. In fact, the child has one of his grandparents and one of his grandparents.
By comparison, a two-breed dog is more beautiful. The gap between straight children and straight women is relatively small, but there is a gap between straight grandchildren or straight grandchildren, if there is a dog that is just a general appearance (that is, a single blood), the product is slightly inferior to the double blood. As for good breeding, there is no difference between purebred golden wool.
If you can tell the difference, look at the dog's chip, the dog out of the big kennel has it.
If it's just American and English, it's called a string. There's no American English for pet-rated golden retriever. It's almost all strings.