Quote from oldtime:
I had a friend who got a job training horses out there at Bay Meadows early in the morning. He was just a little itty biity guy, about half the size of a normal human being.
I asked him if the races were fixed
He said, "The one you have to watch out for is the one that is not fixed. In that race, anything can happen."
slight exaggeration. and if you're worried about rigging, I suggest something besides the markets.