A St. Louis native signed by the Browns, Sievers was the American League Rookie of the Year in 1949, batting .306 with 16 home runs and 75 RBI. He hit just .238 the following season, then was hindered by a shoulder separation suffered while making a diving catch in 1951; after reporting early for spring training in 1952, he dislocated his right arm during infield practice. The Browns traded him to the Senators for Gil Coan in February 1954. In Washington, Sievers became a favorite of Richard Nixon (then vice president), driving in 100 or more runs and playing at least 144 games each year from 1954 through 1958. In 1957, though his club came in last, Sievers led the AL with 42 home runs and became the first Senator to win the RBI crown (114) since Goose Goslin in 1924. He tied an AL record in July and August of 1957 by homering in six consecutive contests – a mark since eclipsed by Don Mattingly. He remained productive through 1963 with the Phillies; that year, he matched Jimmie Foxx as the only players to pinch hit grand slams in both the AL and NL. In mid-1964 he was sold to the expansion Senators. He acquired his nickname as a high school basketball player, from hanging around the “cage” all the time.