Barry Irwin on Kentucky Derby, Race Horse Investing

The Kentucky Derby, held in Louisville, Ky., is the most famous horse race in the world and has been called the most exciting two minutes in sports. Its winners, including Secretariat, Seattle Slew and Affirmed, rank among the most celebrated horses in racing history. But for all the adulation, the Run for the Roses has a mixed record in producing top racing sires.

The 138th Kentucky Derby on May 4, 2013, has already dealt a surprise: Black Onyx, which had been running in the No.1 post position at odds of 50-1, has scratched and won't be running. That changes the odds for a lot of horses in the race. The former favorite, Orb, is now at 6-1. The new favorites are Revolutionary and Goldencents at 5-1.

Kentucky Derby champion Animal Kingdom is the 2-1 favourite for Saturday's 136th Preakness Stakes at Pimlico Race Course.The three-year-old colt will battle 13 others over the 1 3/16-mile Preakness, the second of three races that make up the horse racing's Triple Crown.The third and final leg of the Triple Crown is the $1 million Belmont Stakes on June 11. Not since Affirmed in 1978 has there been a colt that has swept all three races.Animal Kingdom is owned by Team Valor International.

When the horses break from the gates on Saturday for the 139th Kentucky Derby, Goldencents will draw more interest than usual from casual sports fans, thanks to the name of one of his owners: Rick Pitino.

What do you call your horse if you made your millions in the oil business? Frac Daddy, of course. But it's one thing to have your cheekily named mare toil in obscurity. It's another to have the whole world watch it run for the roses.