Born: July 13, 1940
Jackie Delane Aker is an American former Major League Baseball right-handed relief pitcher. Aker was used exclusively in relief. He appeared in 495 games, none as a starter, and was one of the American League's best closers of his era. He is of Potawatomi Indian ancestry.
Aker was originally signed as an outfielder by the Kansas City Athletics and led the Nebraska State League in stolen bases in his first year, 1959, before being converted to pitching before the 1960 season. He made it to the majors as a side-arming sinkerballer, pitching for the Kansas City/Oakland Athletics (1964–1968), Seattle Pilots (1969), New York Yankees (1969–1972), Chicago Cubs (1972–1973), Atlanta Braves (1974), and New York Mets (1974). During an 11-year baseball career, Aker compiled 47 wins, 404 strikeouts, a 3.28 earned run average, and 123 saves, an impressive total at the time.