To answer your original question, I am assuming they are the same dog.
As to whether people breed dogs before matching them, not usually, though I myself don't think it affects much. (You might want to read an experiment I personally did in the thread
Does Breeding Affect Performance?.)
As far as breeding performance dogs goes, if you're LINEbreeding, then the dog you're linebreeding on
should be one helluva good dog. If you linebreed on mediocrity, you'll get mediocrity. If you linebreed on greatness, you will get greatness. The twist (that throws so many people off) is that you won't ALWAYS get great dogs, but an average dog
linebred on a great dog can and will produce great dogs ... especially if he's bred to relatives who have this same great dog in there ... whereas an average dog
linebred on average dogs never will.
People who say linebred dogs can't fight only say this because the dogs they linebred on SUCK. I can assure you that dogs that are linebred CORRECTLY not only can fight, they can outproduce the daylights out of most mixed-bred mutts.
The key to keeping a family of dogs in the winner's circle is simply this: A GOOD EYE for a dog and GOOD TASTE in breeding decisions.
If you don't know what a good dog looks like, you will never breed good dogs consistently.
If you don't make intelligent breeding decisions, you will never breed good dogs consistently.
But if you know what a good dog looks like, and if you make intelligent breeding decisions ... which means MANAGING THE GENE POOL YOU HAVE ... and KEEPING the good in there ... then you can breed good dogs perpetually, for as long as you want.
But the "good" has to be IN THERE, genetically, in order to do this; you can't make "something" out of nothing.
That "something" has to be IN THERE, which (in our terms) means the genetic potential for a
game, tough, talented, bad ass dog to come out.
If it's not maintained in your genetic management, then it's not coming out in your pups. Like a red nose, it doesn't have to show up every generation, but it's got to be IN THERE (up close is better), and KEPT in there, in order to come back out in another litter.
Jack