I believe anyone who doesn't show or health test is a byb.

My summer school teacher this summer was my definition of a good breeder. She breeds Prembroke welsh corgis. She lives with her elderly father who can help. She travels around the country showing, doing agility, obedience, conformation, tracking and herding with them. She also judges many akc events. She had a litter while I was in her class and she would always talk about them, she had homes lined up for them before they were even born if one was sick she didn't even resist taking them to the vet. One morning two of her females got in a fight and she had to go to the vet before she came to school and didn't even flinch coming to school with blood and hair on her.