Bold Ruler
Secretariat was sired by Bold Ruler, who led the North America sire list eight times, more than any other stallion in the 20th century. He also led the juvenile (two-year-old) sire list a record six times. Before Secretariat's Triple Crown run, Bold Ruler was often categorized as a sire of precocious juveniles that lacked stamina or did not train on past age two. However, even before Secretariat, Bold Ruler actually had sired 11 stakes winners of races at 10 furlongs or more. Ultimately, seven of the ten Kentucky Derby winners in the 1970s can be traced directly to Bold Ruler in their tail male lines, including Secretariat and fellow Triple Crown winner Seattle Slew.