"I'd get the Daily Racing Form ahead of time and figure out the probability of each horse winning the race. Then I would compare those percentages to the odds," said Buffett, who bet from $6 to $10 to win. "Sometimes you would find a horse where the odds were way, way off from the actual probability. You figure the horse has a 10 percent chance of winning, but it’s going off at 15-to-1."