The 1929 American League campaign began with two of the greatest players in the history of the circuit having announced their retirements during the offseason. Both Ty Cobb and Tris Speaker called it quits at the conclusion of the 1928 season, bringing to an end the careers of two of the most legendary outfielders ever to play the game. Cobb retired as the all-time leader in numerous offensive categories, including batting average, stolen bases, runs scored, runs batted in, hits, games played, and at-bats. Speaker ended his career with a .344 lifetime batting average, an all-time record 793 doubles, and a reputation as perhaps the greatest defensive centerfielder in baseball history.
Once the regular season got underway, the Philadelphia Athletics replaced the Yankees as the American League's dominant team, running away with the 1929 A.L. pennant by finishing 18 games in front of second-place New York, with a record of 104-46. The combination of Philadelphia’s rapid development into a powerhouse team and the gradual aging of New York's pitching staff enabled the A’s to capture their first league championship in 15 years.
Connie Mack built his team largely on outstanding pitching and the powerful bats of Jimmie Foxx, Al Simmons, and Mickey Cochrane. The A’s staff of Lefty Grove, George Earnshaw, Eddie Rommel, Rube Walberg, and aged reliever Jack Quinn recorded the lowest team ERA in the junior circuit – a mark of 3.44 that made them the only A.L. club to post a sub-4.00 ERA. Grove and Earnshaw anchored Philadelphia’s starting rotation. Grove finished 20-6, for a league-leading .769 winning percentage. He also led the league with a 2.81 earned run average and 170 strikeouts, threw 275 innings, and completed 19 of his 37 starts. In his first full major league season, the 29-year-old Earnshaw led the league with 24 victories, and he also placed among the leaders with a 3.29 ERA, 149 strikeouts, and 254 innings pitched.
Defending A.L. MVP Mickey Cochrane had an outstanding offensive season, batting .331, driving in 95 runs, and scoring 113 others. Establishing himself as a major offensive force for the first time, 21-year-old Jimmie Foxx placed among the league leaders with 33 home runs, 118 runs batted in, 123 runs scored, a .354 batting average, a .625 slugging percentage, and 103 bases on balls. He also topped the circuit with a .463 on-base percentage. Meanwhile, Al Simmons led the American League with 157 runs batted in and 373 total bases, placed second with a .365 batting average and a .642 slugging percentage, and finished third with 34 home runs and 212 hits. Although the A.L. chose not to select an official MVP at season’s end, The Sporting News named Simmons its "unofficial" winner at the end of the year. At the same time, another “unofficial” poll taken of the Baseball Writers Association of America curiously named Cleveland first baseman Lew Fonseca the league's Most Valuable Player. Although Fonseca led the league with a .369 batting average, he hit only six home runs, drove in just 103 runs, and scored only 97 others.
The A’s subsequently faced the Chicago Cubs in the World Series, which began with one of the gutsiest gambles in the history of the Fall Classic. Instead of starting either Grove or Earnshaw in the opening contest, Connie Mack sent seldom-used, 35-year-old junk-baller Howard Ehmke to the mound to face Chicago’s predominantly right-handed hitting batting order. Keeping Chicago’s lineup off balance the entire game with his assortment of slow pitches, Ehmke compiled a then-record 13 strikeouts, en route to posting a 3-1 victory. The A’s took three of the next four contests as well, finishing off the Cubs in only five games. The highlight of the Series took place in Game Four, when Philadelphia overcame an 8-0 deficit with a bizarre 10-run seventh inning that included two balls lost in the sun by Chicago outfielder Hack Wilson.
Although the A’s were the American League’s dominant team in 1929, several players on other clubs performed exceptionally well for their respective teams. Second baseman Charlie Gehringer had an outstanding all-around year for the sixth-place Tigers, leading the league with 131 runs scored, 215 hits, 19 triples, and 27 stolen bases, while also topping all players at his position in putouts and fielding average. Teammate Dale Alexander finished near the top of the league rankings with 25 home runs, 137 runs batted in, 215 hits, and 363 totals bases, while batting .343 and scoring 110 runs.
Babe Ruth and Lou Gehrig both had extremely productive years for the second-place Yankees. Ruth led the league with 46 home runs and a .697 slugging percentage, while also finishing among the leaders with 154 runs batted in, 121 runs scored, 348 total bases, and a .430 on-base percentage. Gehrig finished second to Ruth with 35 home runs, and he also placed in the top five with 126 runs batted in, 127 runs scored, 122 bases on balls, a .431 on-base percentage, and a .584 slugging percentage.
Other notable events from around the league and players who distinguished themselves over the course of the season included:
• January 22 - The New York Yankees announced they intended to begin wearing numbers on the backs of their uniforms. They subsequently became the first baseball team to do so. The first numbers were based on positions in the batting order; thus, Babe Ruth wore number 3 and Lou Gehrig wore number 4. A few weeks later, the Cleveland Indians announced they also intended to begin putting numbers on their uniforms. By 1931, all American League teams used them. It wasn’t until 1933, though, that all National League players were numbered.
• May 13 - At League Park, the Cleveland Indians defeated the New York Yankees, 4–3, in the first game played in Major League history in which players from both teams wore uniform numbers on the back of their jerseys.
• May 24 - The Detroit Tigers defeated the Chicago White Sox 6-5 in 21 innings. Winning pitcher George Uhle pitched 20 innings to earn his eighth win of the season with no losses. The losing pitcher was Ted Lyons, who worked all 21 innings for Chicago.
• August 11 - Babe Ruth hit his 500th career home run in the second inning off Willis Hudlin during a 6-5 loss at Cleveland's League Park. The homer was Ruth's 30th of the year.
• October 9 - Jimmie Foxx hit a pair of home runs to lead the A's to a 9-3 victory in Game Two of the World Series.
• October 12 - Behind 8-0, the Philadelphia Athletics exploded for a World Series record 10 runs in the seventh inning to win Game Four of the Fall Classic, 10-8. Mule Haas delivered a three-run inside the park home run during the inning.
• October 14 - Down 2-0 with one out in the ninth inning, the A's scored three runs to claim their first World Championship since 1913. After Mule Haas tied the score with a two-run homer, Al Simmons doubled, Jimmie Foxx walked, and Bing Miller doubled Simmons home, thus winning the game and the Series.
• Tormented by his failure to motivate the complacent Yankees, exhausted almost beyond endurance, Miller Huggins entered the hospital on September 20 after an ugly blemish under his left eye refused to disappear. Five days later, he died of blood poisoning. Several of the pallbearers at his funeral were players whom he managed.
- 1929 World Series, Al Simmons, American League, Babe Ruth, Bing Miller, Charlie Gehringer, Chicago Cubs, Connie Mack, Dale Alexander, Eddie Rommel, George Earnshaw, George Uhle, Hack Wilson, Howard Ehmke, Jack Quinn, Jimmie Foxx, Lefty Grove, Lew Fonseca, Lou Gehrig, Mickey Cochrane, Miller Huggins, Mule Haas, New York Yankees, Philadelphia Athletics, Rube Walberg, Ted Lyons, Tris Speaker, Ty Cobb, Willis Hudlin