I don't know, the CH Bad Billy dogs were about as ringwise as I have ever seen. My CH Costello was 7/16ths CH Bad Billy/Hannibal breeding, and he was a tremendously smart dog. He has thrown that same pit intelligence into a high percentage of his descendants now generation after generation. You're right, some good dogs have half of their pedigree inbred or linebred. I find the best ones to breed to after they have performed will have the entire pedigree linebred. Keep breeding to the higher end animals from your yard as you mentioned, and you will continue to raise the quality of the line.