Jim Wolf

On October 4, 2001, Wolf served as third base umpire when Rickey Henderson broke Ty Cobb's runs scored record.

Wolf drew criticism from ESPN announcers after he ejected Chicago Cubs starting pitcher Ted Lilly at the start of a game on June 10, 2007 against the Atlanta Braves. Wolf ruled that Lilly had intentionally thrown at the batter's head, and immediately ejected the pitcher. While such a penalty is uncommon without a formal warning to both teams, such action is permitted by baseball's rules.

On May 9, 2010, Wolf was the home plate umpire for Dallas Braden's perfect game. He was the second base umpire for Armando Galarraga's near-perfect game on June 2, 2010. On July 9, 2011, Wolf was the home plate umpire when Derek Jeter got his 3,000th hit against the Tampa Bay Rays.

On August 2, 2015, Wolf was involved in a series of controversial events in a game between the Toronto Blue Jays and the Kansas City Royals. According to National Post sportswriter John Lott, "Umpire Jim Wolf lost control of the game." The controversy was based upon a warning by Wolf to both teams after Blue Jays batter Josh Donaldson was struck by a pitch in the first inning by Edinson Vólquez. The benches were cleared after a number of pitches could have resulted in the Royals' pitcher's ejection, and did not, but a pitch by the Blue Jays' relief pitcher Aaron Sanchez that hit Alcides Escobar immediately resulted in Sanchez being ejected. Former Blue Jays catcher and former Sportsnet baseball analyst Gregg Zaun criticized Wolf for his inability to enforce the warning that was issued in the first.