Pitching coach

In baseball, a number of coaches assist in the smooth functioning of a team. They are assistants to the manager, who determines the lineup and decides how to substitute players during the game. Beyond the manager, more than a half dozen coaches may assist the manager in running the team.

Baseball is unique in that the manager and coaches typically all wear numbered uniforms similar to those of the players. Notable exceptions to this were Baseball Hall of Fame manager Connie Mack, who always wore a black suit during his 50 years at the helm of the Philadelphia Athletics, and Burt Shotton, manager of the Brooklyn Dodgers in the late 1940s, who wore a Dodger 200 cap and a team jacket over street clothes in the dugout. After the widespread adoption of numbered uniforms in the early 1930s, Joe McCarthy, another Hall of Fame manager, wore a full uniform but no number on his back for the remainder of his career (with the New York Yankees, then the Boston Red Sox). Coincidentally, all three men retired during or after the same season — 1950.

Full-time coaches in professional baseball date to 1909, when John McGraw of the New York Giants engaged Arlie Latham and Wilbert Robinson as coaches. By the 1920s, most Major League teams had two full-time coaches, although the manager often doubled as third-base coach and specialists such as pitching coaches were rare. After World War II, most MLB teams listed between three and five coaches on their roster, as managers increasingly ran their teams from the dugout full-time, and appointed pitching and bullpen coaches to assist them and the baseline coaches. Batting and bench coaches came into vogue during the 1960s and later. Because of the proliferation of uniformed coaches in the modern game, Major League Baseball now restricts the number of uniformed staff to six coaches and one manager during the course of a game. There are 268 coaches in MLB.

...
Wikipedia