Peak years Walsh made his major league debut in 1904 with the Chicago White Sox and pitched his first full season in 1906, going 17–13 with a 1.88 ERA and 171
strikeouts. In Game Three of
that year's World Series, which the White Sox won over the
Chicago Cubs in six games, Walsh struck out a then-World Series record 12 batters. He also struck out at least one batter each inning of that game; this feat has since been duplicated twice, once by
Bob Gibson in the
1968 World Series opener and the other time by
Trey Yesavage in Game 5 of the
2025 World Series. From this season through 1912, Walsh averaged 24
victories and 220 strikeouts and posted an ERA below 2.00 five times. He also led the league in
saves five times in this span. His finest individual season came in 1908 when he went 40–15 with 269 strikeouts, 6 saves and a 1.42 ERA, leading the
American League in wins and strikeouts. In 1910, he posted the lowest ERA (1.27) for a pitcher with at least 20 starts and a losing record. Walsh also set an American League record by pitching 464 innings in a season. On August 27, 1911, Walsh
no-hit the
Boston Red Sox 5–0. Interviewed for the 1966 book
The Glory of Their Times, Hall of Famer
Sam Crawford referred to Walsh's use of a pitch that was later outlawed: "Big Ed Walsh. Great big, strong, good-looking fellow. He threw a
spitball. I think that ball disintegrated on the way to the plate, and the catcher put it back together again. I swear, when it went past the plate, it was just the spit went by". In 1910, the White Sox opened White Sox Park, which was soon nicknamed
Comiskey Park by the press in honor of team owner
Charles Comiskey. The name was officially changed to Comiskey Park in 1913. An apocryphal story goes that architect
Zachary Taylor Davis consulted Walsh in setting the park's field dimensions. Choosing a design that favored himself and other White Sox pitchers, rather than hitters, Walsh made Comiskey Park a "pitcher's park" for its entire 80-year history.
Later career Walsh was a workhorse who pitched an average of 375 innings annually during the six seasons of 1907 through 1912. After the 1912 season, Walsh reportedly requested a full year off to rest his arm. Nevertheless, he showed up for spring training the following season, contending, "The White Sox needed me—implored me to return—so I did". Walsh's playing time began dwindling in 1913. He later did some pitching in the
Eastern League, and gave umpiring a try (he umpired 87 American League games during the 1922 season), after which he was a coach for the White Sox for several seasons (1923–1924, 1928–1929). Walsh retired with 195 wins, 126 losses, and 1736 strikeouts. His career ERA of 1.82 is the lowest major league ERA ever posted. He has the third-lowest career
WHIP in MLB history (1.00) and the lowest ever for someone with 10 or more seasons pitched. As a hitter, Walsh posted a .194
batting average (210-for-1,085) with 92
runs, 3
home runs, 68
RBI, 14
stolen bases and 46
bases on balls. ==Managerial record==