A.P. Indy
His sire line almost died out in the 1980s but was revived by Seattle Slew's son A.P. Indy (who was also a grandson of Secretariat on his dam's side). Much like Bold Ruler, A.P. Indy was a Horse of the Year, a leading sire and would go on to become an important sire of sires. In 2014, A.P. Indy's great-grandson California Chrome became the 16th male-line descendant of Bold Ruler to capture an American classic. A.P. Indy is also the grandsire of leading sire Tapit, who sired three winners of the Belmont Stakes in the four years between 2014 and 2017.