One more reason why the Phipps family is good for racing

[Danzig]

i suppose it's so difficult to find any completely free of drugs, he's doing the best he can with what he has to work with.
as for unraced, there are many reasons horses don't race. conformation issues, injuries, illness, or they're just plain too slow.
i remember reading a write up on a good broodmare, she dropped some nice runners, but her poor conformation was felt to be too much of a detriment to racing. a gamble as far as breeding her, but her foals all did fine.