In baseball, the umpire is the person charged with officiating the game, including beginning and ending the game, enforcing the rules of the game and the grounds, making judgment calls on plays, and handling the disciplinary actions. The term is often shortened to the colloquial form ump. They are also sometimes addressed as blue at lower levels due to the common color of the uniform worn by umpires. In professional baseball, the term blue is seldom used by players or managers, who instead call the umpire by name. Although games were often officiated by a sole umpire in the formative years of the sport, since the turn of the 20th century, officiating has been commonly divided among several umpires, who form the umpiring crew. The position is analogous to that of a referee in many other sports.
William Joseph Klem, born William Joseph Klimm, known as the "Old Arbitrator" and the "father of baseball umpires", was a National League (NL) umpire in Major League Baseball from 1905 to 1941. He worked 18 World Series, which is a major league record. Klem was posthumously inducted into the Baseball Hall of Fame in 1953.
Adrián Beltré Pérez is a Dominican former professional baseball third baseman. During his career, Beltré played for the Los Angeles Dodgers, Seattle Mariners, Boston Red Sox, and Texas Rangers in Major League Baseball. He is regarded as one of the greatest third basemen of all time.
Joseph Henry West, nicknamed "Cowboy Joe" or "Country Joe", is an American former baseball umpire. He worked in Major League Baseball (MLB) from 1976 to 2021, umpiring an MLB-record 43 seasons and 5,460 games.
Jerry Blake Layne is an American umpire in Major League Baseball who has worked in the National League between 1989 and 1999, and throughout both major leagues since 2000. He wore uniform number 24 in the NL, but when MLB merged the AL and NL umpiring staffs in 2000, Layne was forced to switch to number 26, as AL umpire Al Clark, who also wore 24, had more seniority. When Clark was fired midway through the 2001 season by MLB, Layne reclaimed number 24 and has worn it ever since. With the retirements of Joe West and Gerry Davis in 2022, Layne became MLB's most senior active umpire.
Ángel Hernández is a Cuban-American umpire in Major League Baseball (MLB). He worked in the National League from 1991 to 1999, and has worked throughout MLB since 2000.
James Michael Wolf is an American Major League Baseball umpire. He joined the major league staff in 1999 after working in the Arizona Rookie League, the South Atlantic League, the California League, the Texas League and the Pacific Coast League. He wears uniform number 28.
Wallace Robert Bell was an American umpire in Major League Baseball (MLB) who worked in the National League from 1992 to 1999 and in both major leagues from 2000 to 2013. He wore the number 36 while a National League umpire, then changed to 35 when the American League and National League staffs were merged in 2000. Tim McClelland wore number 36 longer and he claimed the number.
Michael John Winters is an American former umpire in Major League Baseball who has worked in the National League from 1988 to 1999 and throughout both major leagues from 2000 to 2019, wearing number 33. For the 2011 season, Winters was named a crew chief following the retirements of Jerry Crawford, Mike Reilly, and Chuck Meriwether.
Fieldin Henry Culbreth III is an American former umpire in Major League Baseball (MLB). He worked in the American League from 1993 to 1999 and in both major leagues from 2000 until his retirement in 2021. Culbreth was promoted to crew chief prior to the 2013 season. Culbreth wore number 42 while he was an American League umpire, then changed to 25 in 2000 after the MLB umpires were unified into one crew.
William Scott Miller is an American Major League Baseball umpire who began his career in the American League in 1997. Miller wears number 26. He has been a crew chief since the 2014 season.
Larry Wayne Vanover is an American professional baseball umpire. Vanover worked in the National League from 1991 to 1999. He did not umpire in 2000 and 2001, and since 2002 has umpired across both major leagues. Vanover has umpired two All Star Games, and in the 2016 World Series. He was promoted to crew chief in 2015. Vanover wore sleeve number 28 during his National League tenure, then changed to 27 after his return to the MLB umpiring staff in 2002.
Samuel Woodford Holbrook is an American retired Major League Baseball umpire. He made his MLB debut in 1996 and was promoted to crew chief in 2017. Holbrook worked the World Series in 2010, 2016, and 2019. He retired following the 2022 season.
Christopher Gene Guccione is an American umpire in Major League Baseball. He wears number 68.
Brian Michael Knight is an American professional baseball umpire. He has worked as a full-time Major League Baseball (MLB) umpire since 2011. He wears uniform number 91.
Chadwick Jarrett Fairchild is an American umpire in Major League Baseball. He wore number 75 until the 2014 season, when he changed to number 4. He has worked in one All-Star Game (2013) and six Division Series. In 2017, he worked the ALCS between the Houston Astros and New York Yankees and was the plate umpire for Game 1.
Robert Paul Drake is an American umpire in Major League Baseball. He was named to the Major League staff in 2010, and wears uniform number 8.
Mark Christopher Carlson is an American umpire in Major League Baseball. He wore number 48 until the 2012 season, when his number changed to 6. He was promoted to crew chief for the 2021 season.
Alan Dwayne Porter Jr. is an American Major League Baseball umpire. He umpired his first Major League game on April 5, 2010. He wears uniform number 64.
Nicolas James Lentz is an American umpire in Major League Baseball. He made his debut on April 20, 2016, in Miami. He wears number 59, which was most recently worn by former umpire Jon Byrne.
