Seriously?
Some WB books go back to the mid 1700s, having separate lines for riding almost all the way back. Educate yourself on WB breeding. I recommend this book:
https://horsesdaily.com/article/maki…ttard-gribaldi
WBs aren’t just “sport horses”. There are separate lines for dressage and show jumping. Have been for generations. You simply cannot discard this history. All the years TB breeders have been building towards great racers, WB breeders have been building towards great sport horses.
Even a sport horse TB was born of centuries of RACING lines. It just happens to be good at a secondary career. Can it reliably pass along “secondary career” genetics?
There’s probably a Hanoverian out there who could win a race or two. Let’s throw out the breed rules and say he does. Is there a TB breeder out there who will have even a passing interest in him as a race stallion? Nope.
Yes, the WBs have some TB in them, but these were almost all English TBs which are generally larger with heavier bone than American TBs.
There have been some excellent American TB sport horse stallions in the past 20 years for eventing or the occasional show jumper, but most are retired or sadly gone (Fred, Coconut Grove, etc).
And the sports have changed. The winning TB hunter from 1985 wouldn’t even be in the running in Wellington these days.
Breeding any horse is a crapshoot. Even the best to the best makes duds. But, the history helps stack the odds in your favor. Fewer duds. Better quality duds.
Will I pay extra to stack the odds in my favor? Yes. Yes I will. And so will anyone serious about being competitive today in sport, especially dressage, hunters, or show jumping.