I think that TBs have become like many other breeds that are not necessarily bred for sport Morgans, Draft crosses, Saddlebreds, QHs, etc. it is about the individual. Is the individual appropriate to invest time in? I would not BREED for sport horses from these breeds, but I would consider individuals of the right type, movement, and temperament. The majority of the breeds in most cases are not at all bred for sport but a suitable individuasl can be found in most breeds. There is more likely suitable TBs but nevertheless you must first look at conformation, movement, temperament and sport specific qualities before you imagine there might be talent based on pedigree. If you are a breeder you can find suitable mares in TBs but you really need to prove the mare has sport talent before breeding...modern TBs just can't be assumed to have sport talent based on pedigree today. It is sad but unless the mare or stallion have proven trainability and talent or their offspring have TBs are no longer a place to risk money and time. That is not to say there are not great ones out there waiting to be found but you have to prove them first to convince buyers.