When that county fair was running in the early 90's it took them a while to figure out some of the carnival games spooked the horses and made them break. They had that water pistol balloon game mid stretch. When someone won the game crazy loud bells would ring and if it happened during a race when the field was in the stretch about 1/2 the horses broke. The same thing with that guy they shot out of a canon in the infield, the BOOM had the same effect.