The
Breeders' Cup World Championships is an annual series of
Grade I Thoroughbred horse races, 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. All sites have been in the United States, except in 1996, when the races were at the
Woodbine Racetrack in
Canada.