Failing to breed a New Breed

[Sarah J]

If you breed two horses and they produce a dud, is it likely they will produce another dud if bred together again, or is it completely chance?

[Eska]

I've gotten duds out of parents that both rated 5 for the new breed. There's lots of randomness involved, but you can increase your chances. For example both parents are too small, you'll never get something out of them. If one is too tall and one too small it might just work. The closer the parents are to the standard you're breeding for, the more likely you are to succeed. But even then it can take a number of tries to get what you want.