James Bremond Evans is a former umpire in Major League Baseball (MLB) who worked in the American League (AL) from 1971 to 1999, and ran a professional umpiring school from 1990 through 2012.
Jeffrey Brian Nelson is an American professional baseball umpire in Major League Baseball (MLB), who was named to the National League (NL) staff prior to the 1999 season, and has worked throughout both major leagues since 2000.
Randall Gilbert Marsh is an American former umpire in Major League Baseball who worked in the National League from 1981 to 1999 and throughout both major leagues from 2000 to 2009. Marsh wore the uniform number 30.
Robert Allan Davidson is a former umpire in Major League Baseball (MLB). Nicknamed "Balkin' Bob" and "Balk-a-Day Bob" for his tendency to liberally invoke baseball's balk rule, Davidson was an umpire on the National League (NL) staff from 1982 to 1999, and he was on the combined MLB umpiring staff from 2005 to 2016. He worked one World Series (1992) and several other postseason series.
Gerald Joseph Crawford is a former umpire in Major League Baseball. He first umpired in the National League from 1977 to 1999, then worked in both major leagues from 2000 to 2010.
Edward George Barrett is an American retired Major League Baseball umpire. He joined the American League's staff in 1994, and has worked throughout both major leagues since 2000. Promoted to crew chief in 2013, Barrett worked in 33 play-off series, including five World Series. He retired following the 2022 season.
Lazaro Antonio Díaz Sr. is an American umpire in Major League Baseball wearing number 63, a reference to his year of birth. He joined the American League's full-time staff in 1999, and has worked throughout both major leagues since 2000. Díaz was promoted to crew chief for the 2022 season, becoming the second full time Latino-born crew chief, after Alfonso Marquez.
Kenneth John Kaiser was an American umpire in Major League Baseball who worked in the American League from 1977 to 1999. He spent 13 years in the minor leagues and 23 years in the major leagues, a total of 36 years in professional baseball. Kaiser wore uniform number 21 when the AL adopted numbers for umpires in 1980.
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.
Alfonso Márquez is a Mexican umpire in Major League Baseball (MLB) who worked in the National League in 1999 and has worked throughout both major leagues since 2000. He was promoted to crew chief for the 2020 season, becoming the first full time Latino-born crew chief. Márquez wears uniform number 72, a number he shared with friend and National Hockey League linesman Stéphane Provost.
Richard Raul Garcia is a former umpire in Major League Baseball (MLB) who worked in the American League (AL) from 1975 to 1999. Garcia wore uniform number 19 when the AL adopted numbers for its umpires in 1980.
Marvin Lee Hudson is an American Major League Baseball (MLB) umpire who began his career in the National League in 1998. He has officiated in the 2004 All-Star Game, eight Division Series, two League Championship Series, and two World Series. He wears uniform number 51.
Paul Edward Runge is a former umpire in Major League Baseball who worked in the National League from 1973 to 1997.
Thomas Francis Hallion is a retired Major League Baseball umpire who worked in the National League (NL) from 1985 to 1999 and in both major leagues from 2005 until 2022. He was promoted to crew chief in 2010. Hallion has worn number 20 during his MLB career. He resigned from the NL in 1999 as part of a failed mass bargaining strategy, but he was rehired by MLB before the 2005 season.
Brian Keith O'Nora is an American umpire in Major League Baseball (MLB). He joined the major league staff in 2000, after previously umpiring for the American League (AL) from 1992 to 1999 and wears sleeve number 7.
William Anthony Welke is an American retired Major League Baseball umpire. He joined the major league staff in 1999 and worked the World Series in 2015. Welke was promoted to crew chief for the 2022 season, and retired following that season.
James Norris Reynolds IV is a former American Major League Baseball umpire. He joined the major league staff in 1999 and was promoted to crew chief for the 2020 season. Reynolds wore uniform number 77. He retired following the 2022 season.
Eric Richard Cooper was an American professional baseball umpire, whose Major League Baseball (MLB) career spanned 1999 until his death in October 2019. He wore umpire uniform number 56. As a Major League umpire, Cooper officiated in ten Division Series, four League Championship Series, three Wild Card Games, one All-Star Game, and one World Series.
Bruce Michael Dreckman is an American umpire in Major League Baseball. He wears number 1.
George Drew Coble is an American former professional baseball umpire who worked in the American League from 1982 to 1999. Coble umpired 2,303 major league games in his 18-year career. Coble wore uniform number 37. He was promoted to crew chief in 1991. He umpired in the World Series (1991), two All-Star Games, three American League Championship Series, and two American League Division Series.
