I don't know what's each degree exactly out of my head but you should be really careful putting an animal with PL in the ring. Some luxate very easily and don;t shoot back out it self. The dog can have gameness all he want but all he has left then is 3 legs. I guess your dogs Jack didnt have such bad degree, just a little loose patella's. With something worse then that i personally would never do any sport nor breed the dog cause its a genetic fault. If u still want to do WP the dog make sure the surrounding muscles are very strong.