He was first called "Jim" when he was 17, "Big Jim" when he started playing for the
Chicago White Sox during the 1952 season, and
"Jungle Jim" in 1953 which was initiated by
Chicago Sun-Times sports writer Edgar Munzel. This was due largely to his unorthodox playing style, and for his highly extroverted personality. Rivera threw and batted left-handed; he stood 6 feet tall and weighed 196 pounds during his playing days. In 1949, playing for the
Gainesville G-Men in the
Florida State League, he batted .335 (3rd in the league)/.405/.537(2nd) in 529
at bats and led the league in runs (142), triples (16), and
stolen bases (55), while coming in second in
home runs (13) and
RBIs (102), while on defense he played
center field and had 24 assists. In 1950, he played primarily for the
Pensacola Fliers of the
Southeastern League, for whom in 527 at bats he batted .338(9th in the league)/.388/.552(6th) and tied for the league lead in runs (139) and triples (12), while coming in third in RBIs (135), fifth in home runs (20), and sixth in stolen bases (23), while on defense he played
outfield and had 13 assists. He made his MLB debut at 30 years of age in 1952. In 1953, he led the
American League in
triples (16; he was in the top 7 in the league three other seasons), in 1955 in
stolen bases with 25 (he was second in the league six other seasons), in stolen base percentage in 1957 and 1958 (he was in the top five in five other seasons), and in 1955 in outfield assists (22; he was fourth in the league in one other season), and was the sixth-oldest player in the league in 1961. He was a sparkplug for the 1950s Go-Go White Sox team, eventually winning the American League pennant in
1959. White Sox General Manager
Ed Short said: "Jungle Jim may not have the fattest average in baseball, but he gives the fans a show with his daredevil running and sliding, his terrific fielding, and clutch hitting. He runs in the outfield like a deer, on the bases like an express train, and he throws like a rifle." On
Opening Day in 1961 he asked U.S. President of the United States
John F. Kennedy for his autograph, and after seeing the signature said, signature "What kind of garbage college is that Harvard, where they don't even teach you how to write? What kind of garbage writing is this? What is this garbage autograph? Do you think I can go into any tavern on Chicago's south side and really say the President of the United States signed his baseball for me? I'd be run off." A smart and fast runner, Rivera ran the bases with abandon, sliding into bases on his belly before it was fashionable, and made many a game-saving catch playing right field. A
ground ball hitter, he used his speed to full advantage and was much tougher in clutch situations. However, in
that year's World Series, which the White Sox lost in six games to the
Los Angeles Dodgers, Rivera went hitless in 11 at-bats. At age 40, Rivera appeared in 64 games for the Kansas City A's during the 1961 season, hitting .241 to cap his career. Rivera said
Whitey Ford was the "toughest"
pitcher he ever faced and he liked it when he was called "Big Jim." Rivera had a .256 lifetime
batting average with 83
home runs, 422
RBIs, 503
runs, 155
doubles, 56 triples, and 40 intentional walks with a 106 Power-Speed # and 70.5% stolen base percentage in 1,171
games played. He also had a career total of 160 stolen bases and a lifetime .978
fielding average. As of the beginning of the 2025 season, in Chicago White Sox history in his career he was 7th in Power-Speed #, tied for 14th in intentional walks, 17th in stolen-base percentage, 18th in stolen bases, and tied for 18th in triples. His 90.0% stolen base percentage in 1957 was 8th-best and his 87.5% in 1958 was 12th-best, and his16 triples in 1953 were tied for 11th-most, in single-season team history. In 1962 he had 393 at bats in the minor leagues, batted .229/.354/.422, and stole 19 bases in 21 attempts, as he had 11 assists while playing the outfield. ==Later life==