High Quality Content by WIKIPEDIA articles! The Breeders` Cup World Championships is an annual series of Thoroughbred horse races, most but not all Grade I, operated by Breeders` Cup Limited, a company formed in 1982. From its inception in 1984 through 2006, it was a single-day event; starting in 2007, it expanded to two days. The location changes each year. All sites have been in the United States, except in 1996, when the races were at the Woodbine Racetrack in Canada.