Mackenzie “Mack” Miller, the Hall of Famer who personified the old school of gentleman trainers, died Saturday morning at the Markey Cancer Center at the University of Kentucky in Lexington, where he had been hospitalized since having a stroke Dec. 5. He was 89. Miller and his wife, Martha, lived in his hometown, Versailles, Ky., just west of Lexington. Miller retired from training in 1995 when his longtime client, Paul Mellon, began dispersing his racing stock. Miller was best known for training Mellon’s homebred, Sea Hero, to win the 1993 Kentucky Derby and Travers, but he also trained more than 70 other stakes winners, including Fit to Fight, Java Gold, and Snow Knight, all for Mellon. He was based primarily in New York during his 46-year training career. “Mack was a great, great horse trainer, but an even better human being,” said Hall of Fame jockey Jerry Bailey, who rode Sea Hero to win the Derby. “All I have about him is kind words. He was like a second dad away from home for me. There are probably quite a few characters on the racetrack, but for me, as an impressionable young man in New York at 25, my hooking up with Mack was probably the best thing that ever happened to me.” With the 13-1 upset in the 119th Derby by Sea Hero, Miller and Mellon became known as a horse racing version of the Sunshine Boys for capturing the sport’s greatest prize at the ages of 71 and 85, respectively. That success was widely acknowledged and applauded as a much-deserved crowning achievement, given their lifelong devotion to racing and their genteel manner. Miller was born Oct. 16, 1921. He attended the first Keeneland meet in 1936 and dropped out of college a few years later to join the Air Force and serve in World War II. He worked with broodmares at Calumet Farm for several years before opening a public stable in 1949. He trained his first stakes winner, Oil Painting, in 1955, and his first champion, Leallah, the co-champion 2-year-old filly of 1956. Miller became the private trainer in the mid-1960s for industrialist Charles Englehard, for whom he trained such top horses as Assagai and Hawaii, both grass champions, as well as Halo, Mr. Leader, and Tentam. Miller became the private trainer for Mellon in 1977. Miller was inducted into the National Museum of Racing Hall of Fame in 1987 in Saratoga Springs, N.Y., during the same summer when Java Gold won the Whitney before wheeling back two weeks later to defeat the likes of Alysheba and Bet Twice in an epic renewal of the Travers. Besides his feats as a trainer, Miller also was an accomplished breeder. In partnership with R. Smiser West, he bred champions Chilukki and De La Rose, along with Kentucky Oaks winner Lite Light and other stakes winners. Mellon died in 1999 and West died in 2006. A memorial service for Miller has been set for noon Eastern on Tuesday at the Versailles Presbyterian Church. Burial will be private.