Depends what you mean by losingest. The manager who has lost the most games, Connie Mack (3948), has also won the most games, because he managed the most games - 7755 games over 53 seasons - waaaaaaay more than anyone else. 16 managers have managed at least one game, and failed to win any - for a .000 winning percentage. The most games below .500 a manager is is 242, by Jimmie Wilson who went 493-735 in the 30s and 40s managing some pretty bad Phillies and Cubs teams. That's a .401 winning percentage though, which is pretty bad, but nowhere near the worst winning percentage for a manager who "qualifies," (320 career games managed, according to Baseball-reference.com) - that distinction is held by Doc Prothro, who guided the Phillies to a 138-320 record between 1939 and 1941, for a paltry winning percentage of .301.
Take your pick.
pete rose
Lou Pinella, Chicago Cubs
Tommy Lasorda
Major League Baseball.
Bud Selig is the Commissioner of Major League Baseball.
Chuck Tanner Major League Baseball Manager of the Year Award was created in 2007.
frank robinson
No. Dallas Green was a major league baseball manager.
pete rose
Lou Pinella, Chicago Cubs
The most successful of active major league managers is Tony La Russa of the St. Louis Cardinals.
Larussa
i think it would be sports and colledge.
Tommy Lasorda
al lopez Cleveland Indians 1951
major league baseball
pretty much all of them. billy beane