I realize this is probably a really, really stupid question, but couldn't thoroughbred races do starting gates like standardbred races? IE, a moving "fence" that the horses ride up behind in their designated spots then are guided to a certain position before fence draws away and the actual race begins a small stretch after that? Or is that immediate zero-to-sixty vital to TB racing and the ability to do so is part of what makes a TB a TB? I ask since it seems like you'd get less freakouts than putting the horse in a cage to explode out of at the start.
Jocks and ground crews must have nerves of steel to work with horses who freak out like Quality Road did.
One of the problems with the movable start in the TB world is the speed at which they start (galloping) and the strength of the horses. It would be impossible to hold that many TB's together at a trot or canter, runoffs would be disasterous.
Another thing to consider is the difference in racing surfaces. TB's run on dirt, when it rains they run on mud (excluding synthetics), and they also run on turf, which when it's soft a vehichle would tear up. Compared to an almost paved road that the Standerbreds race on.
In response to Acertainsmile
This side, the youngsters are often sent to a 'pre-training' yard to learn the basics before going on to their trainers. Or the trainers do the work themselves, often using highly experienced members of their staff to back and then prepare the horses to race, which will most certainly include going into the stalls.
In Britain, the trainers are scattered all over the country and the horses travel to the race meetings (at 60 courses). Often they do not even need to stay over night. So the gate training is at home, in a peaceful atmosphere, and, I suspect, as often as needed. I believe that some horses are retired from racing if they will not go into the stalls. Good thing there are lots of other disciplines suitable for TBs.
A previous post commented that American racing is flat out from the start and the British style is more a gradual increase in speed. On turf, over distances of up to 2 miles or more, the start is not as important. In jump racing, they don't even bother with a piece of string sometimes!
Thanks again Willesdon, while never having the opportunity (yet) to get over there, I've known plenty of folks that have trained and ridden in the U.K. Shame I've never had this discussion with them! I believe that was me saying that the start wasn't as important over there vs over here because of position and length of the races (generally speaking).
I've personally known several horses that either refused to be loaded or were just such bad actors that their careers were also cut short, or non existant. Someimtes it's worth listening to what a horse is trying to tell you!
As for jump races, we do not use a gate over here either. :)