Major League Baseball is trying to speed up the pace of play, and one of their solutions is to limit the number of in-inning pitching changes. As my dad always likes to say, “They need to stop with that righty/lefty cr*p.” Poetic or not, the Commissioner’s Office heard fans complaints, presumably conducted their own research, and decided the game would be better off without pitchers entering the game to face one or two hitters.
The new rules that go into effect during the 2020 season will prevent managers from changing pitchers before they face a minimum of three batters, or at least finish an inning.