
I have also to agree with Westcoast - to breed quality puppies in most cases you need a quality bitch as a brood bitch that also has good health test results. The pedigree is important, but if the bitch does not have any of the desirable features of a breed, it really matters very little how good the pedigree.
From our experience having owned and a popular stud, every time he went to a less than quality bitch the resulting litter was not as good as either parent, although he did tend to improve on the bitch in certain areas eye colour and shape and he improved feet and gave substance to bitches that were lacking in bone. But his best pups came from the quality bitches with good dogs/bitches behind them - a number of Champions were produced worldwide.
You can improve on a plain bitch at each generation, but it takes a long time and a lot of hard work and delving deep into pedigrees.
Although there are those who say that you need as many bitches to be used as possible to increase genetic diversity.
Thre will never be an easy answer.