Near the end of the first decade of the double-Bills' guidance, the Cubs won the NL pennant in 1929 and then achieved the unusual feat of winning a pennant every three years, following up the 1929 flag with league titles in 1932, 1935, and 1938. Unfortunately, their success did not extend to the Fall Classic, as they fell to their AL rivals each time. The '32 series against the Yankees featured Babe Ruth's "called shot" at Wrigley Field in Game 3. There were some historic moments for the Cubs as well; In 1930, Hack Wilson, one of the top home run hitters in the game, had one of the most impressive seasons in MLB history, hitting 56 home runs and establishing the current runs-batted-in record of 191. That 1930 club, which boasted six eventual Hall of Famers (Wilson, Gabby Hartnett, Rogers Hornsby, George "High Pockets" Kelly, Kiki Cuyler and manager Joe McCarthy) established the current team batting average record of .309. In 1935 the Cubs claimed the pennant in thrilling fashion, winning a record 21 games in a row in September. The '38 club saw Dizzy Dean lead the team's pitching staff and provided a historic moment when they won a crucial late-season game at Wrigley Field over the Pittsburgh Pirates with a walk-off home run by Gabby Hartnett, which became known in baseball lore as "The Homer in the Gloamin'".

What year did Hack Wilson have one of the most impressive seasons in MLB history?