Born in West Springfield, Massachusetts, Durocher joined the New York Yankees briefly in 1925 before rejoining the club in 1928 as a regular, if unspectacular, player. Babe Ruth, who Durocher disliked intensely after Ruth accused Leo of stealing his watch, nicknamed him "The All-American Out".

Durocher was a favorite of Yankee manager Miller Huggins who saw in him the seeds of a great manager -- the competitiveness, the passion, the ego, the facility for remembering situations. Durocher's outspokenness did not endear him to Yankee ownership, and his habit of passing bad checks to finance his expensive tastes on clothes and nightlife, annoyed Yankee general manager Ed Barrow.

After helping the team win its second consecutive World Series title in 1928, and demanding a raise, he was waived before the 1930 season.

Durocher spent the remainder of his professional career in the National League. After three years with the Cincinnati Reds, he was traded to the St. Louis Cardinals in mid-1933. That team, whose famous nickname "Gashouse Gang" was supposedly inspired by Leo, were a far more appropriate match; in St. Louis, Durocher's characteristics as a fiery player and vicious bench jockey were given full rein. Durocher remained with the Cardinals through the 1937 season, captaining the team and winning the 1934 World Series (their third title in nine years) before being traded to the Brooklyn Dodgers.

Primarily a shortstop, Durocher played through 1945 (excluding the 1942 and 1944 seasons), and was known as a solid fielder but a poor hitter. In 5,350 career at bats, he batted .247, hit 24 home runs and had 567 RBI. He was named to the NL's All-Star team three times - once with St. Louis, and twice with the Dodgers.

While with the Dodgers in 1939, however, Durocher assumed the position for which most would remember him, that of manager. As a manager, his temperament came into its own, and the most enduring images of Durocher are of him standing toe-to-toe with an umpire, vehemently arguing his case until his inevitable ejection from the game. In assembling his teams, he valued the same characteristics in his players, his philosophy best expressed in the widely quoted - but misunderstood - phrase for which he now best remembered: "Nice guys finish last".

In an interview while with the Dodgers, Durocher had been commenting on the common belief at the time that if a team's players got along well, they would naturally play better than teams with difficult or irascible players; noting some of the players on the Giants who had reputations as personable individuals, he observed that they were all "nice guys", but would nonetheless finish last, summing up his argument with, "Nice guys; finish last." The remark was quoted accurately in the published interview, but came to take on a different meaning when some incorrectly thought he meant that such a team would finish last because it included "nice guys", when in fact he had meant that there was no correlation between the personalities on a team and their level of play.

Coming off six straight losing seasons, he made a quick turnaround; apart from the war year of 1944, he would not have a losing campaign with the team. In 1941, just his third season of managing, he led the Dodgers to the National League pennant (their first in 21 years) with a 100-54 record. Durocher managed the Dodgers continuously until 1946, but clashed regularly with Commissioner Albert "Happy" Chandler. Throughout his tenure Leo had been warned away from his friends, many of whom were gamblers, bookmakers or had mob connections, and who had a free rein at Ebbets Field. (He was particularly close with actor George Raft, with whom he shared a Los Angeles house, and admitted to a nodding accquaintance with Bugsy Siegel.)

Furthermore, Durocher encouraged and participated in card schools within the clubhouse, was something of a poolshark himself and a friend to many pool hustlers. He also followed horse racing closely. Matters came to a head when Durocher's affair with married actress Laraine Day became public knowledge, drawing criticism from Brooklyn's influential Catholic Youth Organization; the two later eloped and married in Mexico in 1947, divorcing in 1960.

During spring training 1947, Durocher became involved in an unseemly feud with Yankee owner Larry MacPhail. In person, Durocher and MacPhail exchanged a series of accusations and counter-accusations, with each suggesting the other invited gamblers into their clubhouses. In the press, a ghostwritten article appeared under Durocher's name in the Brooklyn Eagle, seeking to stir the rivalry between their respective clubs. Under pressure from MacPhail (a close friend of Chandler who was pivotal in having him appointed Commissioner), Chandler suspended Durocher for the 1947 season for "association with known gamblers".

Prior to being suspended, however, Durocher played a noteworthy role in erasing baseball's color line. In the spring of 1947, he let it be known that he wouldn't tolerate the dissent of those players on the team who opposed Jackie Robinson joining the club, stating:

"I don't care if the guy is yellow or black, or if he has stripes like a f***ing zebra. I'm the manager of this team and I say he plays." He greatly admired Robinson for his hustle and aggression, calling him "a Durocher, with talent." And Durocher liked to say of Eddie Stanky, the sparkplug on his 1951 pennant winning Giants team,

"He can't hit, he can't field, he can't run -- all he can do is beat you." For Durocher, there was no greater compliment. He would return for the 1948 season, but his outspoken personality would again cause friction with team executive Branch Rickey, and Durocher was fired mid-season. He was immediately hired, however, by the Dodgers' cross-town rivals, the New York Giants. He enjoyed perhaps his greatest success with the Giants, and possibly a measure of sweet revenge against the Dodgers, as the Giants won the 1951 NL pennant in a playoff against Brooklyn, triumphing on Bobby Thomson's historic game-winning home run.

And with the Giants in 1954, Durocher won his only World Series championship as a manager by sweeping the heavily favored Cleveland Indians, who had posted a record of 111-43 in the regular season.

Durocher managed the Giants through 1955 before leaving the field, working as a television commentator. He served as a coach for the Dodgers, now relocated in Los Angeles, from 1961 to 1964.

Durocher returned to the managerial ranks in 1966 as leader of the Chicago Cubs, whom he managed until 1972. While with the Cubs, Durocher had regular disagreements with their aging superstar, Ernie Banks, whose injured knees made him a liability but whose legendary status made him impossible to bench. Durocher also nearly came to blows with Cubs star Ron Santo.

The problems would be symbolic of Durocher's difficulty in managing the new breed of wealthier, more outspoken players who had come up during his long career. He then managed the Houston Astros for the final 31 games of the 1972 season and the entire 1973 season before retiring.

Durocher finished his managerial career with a 2008-1709 record for a .540 winning percentage. He posted a winning record with each of the four teams he led, and was the first manager to win 500 games with three different clubs.

Durocher, with Ed Linn, wrote one of the great sports memoirs of all time, "Nice Guys Finish Last." It tells the story of Durocher's life in brisk, vivid colors with a good deal of humor and sass.

Leo Durocher died in Palm Springs, California at the age of 86, and is buried in Forest Lawn, Hollywood Hills Cemetery in Los Angeles. He was inducted into the Baseball Hall of Fame in 1994.