Why do breeders prefer to use sister or half-sister of stakes winner?

Question

Why do breeders prefer to use sister or half-sister of stakes winner?

Answer 1

If you are breeding for sales, buyers prefer stakes winners in the dams 1st generation of her pedigree.  The theory is that breeding stakes winners to stakes winners produces stakes winners

Answer 2

Stakes races are the best kind of race to win so the theory goes that if there is a stakes winner already in the family any other relatives are more likely to be stakes winners too.

Plus stakes winning horses narurally cost more to buy, so by purchasig a sisiter or half sister to a stakes winning horse you pay less but are still hoping to tap into the good bloodline.

Of course this does not always work, but if breeding good horses was easy we'd all be doing it!