? about Line Breeding

A few years back I read alot of material on linebreeding horses. An author "Robert Denmark" wrote a really good book I believe the title is " The King Ranch Horses". Robert Kleberg was trying to duplicate A horse named Ole Sorrel, Real good reading. But a little later I listened to a interview with Tio Kleberg, I believe Red Steagal was the interviewer. He recognized they were carrying it too far. That was when the ranch purchased Peppy San Badger, along with bloodlines of other top horses. I believe this goes to show whether its linebreeding or inbreeding, watched carefully can be a good thing. But the time for the outcross can always be expected. Also and I DON'T know this for sure, but always heard of the King ranch driving herds of bad horses off the ranch. Like I stated I don't know for sure, but it would make sense. Breeding horses in this fashion has always been a good debate and I'm sure it will be the same with dog breeders!