My favorite Kentucky Derby winner was named Regret. She was the first filly to ever win the Kentucky Derby! That was in 1915. The other two fillies that won The Kentucky Derby were called Winning Colors and Genuine Risk.
Regret became the first of only four horses to ever win all three Saratoga Race Course events for two-year-olds: the Saratoga Special Stakes, Sanford Stakes and Hopeful Stakes. The following year she won the 1915 Kentucky Derby, her first race as a three year old, and became the first filly of three to do so. This brave filly was also the first undefeated horse to win the Kentucky Derby, and had only three starts prior to the race. Retrospectively, Regret was named American Horse of the Year.
Out of 11 starts in four seasons (1914–1917), Regret won nine, and placed second in one. The only race she was not placed in was the 1916 Saratoga Handicap. Throughout her racing career, she was never beaten by a female horse.
Regret was inducted into the National Museum of Racing and Hall of Fame in 1957.
By the way, the 2018 Run for the Roses was run on Saturday. Have a look who won here.