Minor leagues Miller was assigned to the
Class-D Salisbury Cardinals in 1949, where he had an 8–13
won–loss record with a 4.29
earned run average (ERA) as a starter. He began the 1952 season with the
Triple-A Columbus Red Birds, going 11–5, with a 2.34 ERA, throwing four
shutouts in 13
starts.
Major leagues St. Louis Cardinals In August 1952, Miller was called up by the Cardinals. He regressed in 1953 with the Cardinals, with a 5.56 ERA, with over half of his appearances coming as a relief pitcher. He split the 1954 season between Columbus (where he was mostly a starting pitcher) and the Cardinals (where he pitched the vast majority of his games in relief). Miller pitched in only three games for the Cardinals in 1956, when he was traded to the Philadelphia Phillies in early May with
Harvey Haddix and
Ben Flowers for
Murry Dickson and
Herm Wehmeier.
New York/San Francisco Giants Miller finished out the 1956 season with the Phillies,still pitching the majority of his games as a starter. After the season ended, the Phillies traded Miller to the New York Giants for
Jim Hearn. but with the Giants, he started only 13 of the 38 games in which he appeared, with a 7–9 record and 3.63 ERA. At 29 years old, this would be his last year in the minor leagues until the end of his career. In 1959, he appeared in 50 games as a relief pitcher, with only 9 starts, with a 8–7 record, eight saves and 2.84 ERA. In 1960 he started only three of 47 games in which he appeared, which would be the last starts of his career. His 17 saves tied
Roy Face for the National League lead. Miller was named an
All-Star for the Giants in 1961, and played in both All-Star games that year. He pitched the final three innings of the July 31 All-Star game, with five strikeouts, the game ending in a tie. Manager
Alvin Dark thought Miller's 1961 season was the best of any relief pitcher who ever played for Dark. "It got so the starters would work seven innings and look to the bullpen expecting to see him running in."
The Sporting News named Miller the National League's
Fireman of the Year. Miller was 12th in NL most valuable player voting that year. In September, the Giants held a Stu Miller Night.
1961 All star game He was involved in one of the more memorable moments in
All Star Game history, albeit for an exaggeration of the event in question. In the ninth inning of the first of two All Star Games (two were played between and ), which was played at
Candlestick Park, a gust of wind caused Miller to sway slightly, resulting in a
balk, which advanced
Roger Maris to second and
Al Kaline to third. In the embellished version, it is reported that the wind gust blew the 165-pound Miller off the
pitcher's mound. Kaline later scored on an error by
Ken Boyer on
Rocky Colavito's ground ball, which tied the score at 3–3. One batter later, the wind caused catcher
Smoky Burgess to drop
Tony Kubek's foul pop-up for an error. Miller bailed Burgess out by striking out Kubek, and after
Yogi Berra reached base on
Don Zimmer's error, Miller got
Hoyt Wilhelm to fly out to left to end the inning. In the top of the 10th inning, the defense behind Miller almost did him in;
Nellie Fox walked and scored all the way from first on Boyer's three-base throwing error (the second by Boyer in as many innings) on Kaline's ground ball. Miller's teammates bailed him out in the bottom of the inning and made him the winning pitcher;
Hank Aaron singled and scored on a double by Miller's Giant teammate
Willie Mays to tie the score, then Mays scored the winning run on
Roberto Clemente's single. In 1962, although the Giants went to the World Series, Miller had his highest ERA since 1956, posting a 4.12 mark in 59 games (107 innings pitched), going 5–8 with 19 saves. He pitched in two games in the World Series, going 1.1 innings with one hit, two bases on balls and no runs allowed.
Baltimore Orioles He responded with a strong 1963 season in which the Associated Press reported, "Little Stuart has never been better." his ERA was 2.24, lowest since his rookie season. The Sporting News named him the AL Fireman of the Year, joining
Lindy McDaniel as the first players to win the award twice; and becoming the first player to win it in both leagues. Miller pitched 66 games in relief (5th in the AL) with 22 saves (3rd in the league) and a 3.06 ERA. Miller finished seventh in MVP voting in
1965, a year in which he had a 14–7 record and 24 saves (tied for 2nd in the AL) in 67 appearances (5th in the AL). His 1.89 ERA that season was the Orioles record for pitchers who worked at least 100 innings in a season until it was surpassed by
Trevor Rogers' 1.81 in
2025. In 1966, the 38-year-old Miller was a key pitcher for the
world champion Orioles. He pitched in relief in 51 games, with a 9-4 record, 18 saves, and a 2.25 ERA over 92 innings. Miller did not appear in the World Series, a 4–0 Orioles sweep, as their starting pitchers completed Games 2-4, and
Moe Drabowsky was the only reliever needed in Game 1. On April 30, 1967,
Steve Barber and Miller combined to pitch a
no-hitter for the Orioles against the
Detroit Tigers, but would lose 2–1. Miller entered after Barber, who walked ten batters, gave up the tying run on a
wild pitch with two outs. A ground ball to shortstop
Luis Aparicio should have ended it for Miller, but when Aparicio threw the ball to second baseman
Mark Belanger, Belanger misplayed it, his
error allowing the winning run to score. Ironically, Belanger, who went on to replace Aparicio as the Orioles' shortstop, is considered one of baseball's greatest defensive players with the second highest Defensive
WAR (wins above replacement) of any player in baseball history. On May 14, 1967, he gave up
Mickey Mantle's 500th career home run.
Career and honors Miller was among the top relief pitchers of his era, and is a member of the Giants Wall of Fame and Orioles Hall of Fame. Miller was named the Sporting News Reliever of the Year in 1961 and 1963.Over 16 major league seasons, Miller had a 105–103 record with 153 saves and a lifetime ERA of 3.24. He started 93 of the 704 games in which he appeared, and averaged 6.2 strikeouts per nine innings and 3.2 bases on balls per nine innings. credited Miller for helping him become a better pitcher. "I learned from guys like Stu Miller. I sat out in the bullpen with him when I was nineteen and watched and listened. It was like graduate school." Baseball Hall of Famer
Harmon Killebrew said Miller was the most difficult pitcher he ever faced. ==Pitching style==