For the race of the same name at Monmouth Park Racetrack, see: Monmouth Regret Stakes.The Regret Stakes is a Thoroughbred horse race for three-year-old fillies run on the turf at Churchill Downs in mid-June near the end of the Spring Meet in Louisville, Kentucky. Set at one and one-eighth miles (9 furlongs), the Grade III Regret currently offers a purse of $100,000 added.The race is named for Harry Payne Whitney's 1915 champion filly Regret, the first filly to win the Kentucky Derby.