He led the AL in losses in 1902 with 21, and led the league in saves in and . In his remarkable season for the Red Sox, as they repeated as AL champions, he started 37 games, completing every one of them for a total of 335 innings pitched, posting a record of 23–14. On June 12, he won a 16-inning contest by a score of 2–1 over the Browns, and four of his next five starts also went at least 10 innings though he only won the first. On the season's final day, October 10, he faced the New York Highlanders in the first game of a doubleheader, with New York needing a sweep to take the pennant from Boston; the opposing pitcher, Jack Chesbro, had already established a modern record with 41 victories. The game went into the final inning tied 2–2 before a wild pitch by Chesbro gave a 3–2 victory, and the flag, to Boston. On September 27, 1905, Dinneen pitched a 2–0 no-hitter against the Chicago White Sox.
Career as an umpire
Dinneen joined the AL umpiring staff on September 12, 1909, just 17 days after his final pitching appearance with the Browns. He umpired in eight World Series, tying the AL record set by Tommy Connolly. He served as crew chief for the 1914, 1926 and 1932 Series. He was also selected to work in the first All-Star game in 1933, calling balls and strikes for the first half of the game before giving way to the NL's Bill Klem. He was the third base umpire for the game on June 23, 1917 in which Ernie Shore replaced Babe Ruth with no one out and a runner on first base in the first inning, after Ruth was ejected for arguing the calls of plate umpire Brick Owens and then striking Owens. Shore retired the runner as well as all 26 batters he faced. Dinneen was the home plate umpire on May 18, 1912, when the Detroit Tigers staged a one-game walkout in protest of Ty Cobb's suspension; using replacement players including team coaches as well as college players in attendance, the Tigers lost 24–2 to the Philadelphia Athletics. Dinneen had his own confrontation with Ruth in the season. On June 19, the outfielder got into an argument with the umpire, and during the next day's game he again insulted the official. In response, AL president Ban Johnson on June 21 sent a letter to Ruth, reading in part: In addition to the no-hitter he pitched, Dinneen also called balls and strikes for five other no-hitters. He remains the only individual in major league history to both pitch a no-hitter and call one as plate umpire. For baseball's inaugural All-Star Game in 1933, Dinneen was assigned to be the home plate umpire. The umps rotated during the game, Bill Klem later taking over for Dinneen behind the plate. In 1946, Dinneen was one of 11 umpires placed on a Roll of Honor by the Baseball Hall of Fame. He threw out the first pitch before Game 2 of the 1953 World Series, the 50th anniversary of his standout World Series performance.
Later life
A lifelong Syracuse resident, he was an investor in a local brewery until 1950. He died at Syracuse Memorial Hospital at the age of 78; his death was attributed to heart disease. He was buried in St. Agnes Cemetery in Utica, New York. His wife, the former Margaret Quinn, died six years previously; he was survived by three sons and a daughter. Dinneen was mentioned along with teammates Chick Stahl and Cy Young in the 2004 revival of the song "Tessie" by Dropkick Murphys.