From BR Bullpen
Timothy Joseph Tschida
 Biographical Information
Tim Tschida has been a long-time major league umpire. He began his career in the California League (1981-1982) and moved on to the Southern League (1983), Dominican Winter League (1983-1984) and American Association (1983-1986). He umpired his first major league game in the American League in 1985 and was also a fill-in for a good part of the 1986 season.
He was a full-time major league umpire from 1987 to 2012. He worked the 1984 Caribbean Series, 1992 All-Star Game, 1998 World Series, 2002 All-Star Game, 2002 World Series and 2008 World Series, in addition to nine Division Series and three League Championship Series. He was designated a crew chief until his retirement. He umpired for 28 seasons and 3,358 regular season games. Away from the field, he has volunteered for Meals on Wheels and Catholic Charities.`
Tschida has been involved in a couple of high-profile ejection of pitchers on charges of doctoring the baseball. On August 3, 1987, he was the home plate umpire when he went to the mound to check out Joe Niekro after finding unusual markings on a number of balls. Niekro was found to have an emery board in his back pocket and was ejected. On June 19, 2012, he was asked by Washington Nationals manager Davey Johnson to check Joel Peralta's glove, and discovered pine tar, leading to another ejection.
Another controversial play happened in the 1999 ALCS when he called out Jose Offerman of the Boston Red Sox even though New York Yankees 2B Chuck Knoblauch had failed to tag him by about a foot and a half, leading to an inning-ending double play.
He was the home plate umpire for Nolan Ryan's seventh and final no-hitter in 1991, as well as for the 2008 no-hitter by Carlos Zambrano against the Houston Astros in a game moved to Milwaukee's Miller Park because of a hurricane in Texas.
Primary Source: MLB.com bio