1929 St. Louis Cardinals
The oldest pitching staff in franchise history belongs to the 1929 team; their average age was 32.3 years for pitchers. The staff allowed 806 runs in 154 games, and they finished the season with a 78-74 record, 4th in the National League.
Only one starting pitcher, Grover Alexander (who happened to be forty-two), had an ERA below 4.00, and the entire team's ERA was 4.66 for the season. The bullpen was significantly younger than the rotation, but it still featured six pitchers on the wrong side of thirty. This pitching staff was nothing to write home about, and you would be hard-pressed to identify one of the players on this roster based solely on familiarity.
1928 St. Louis Cardinals
The previous season featured a pitching staff with an average age of 32.1, marginally younger than the 1929 team. It seems logical that each consecutive season sees the pitching staff getting slightly older assuming the players remain the same. The 1928 St. Louis Cardinals finished the season 95-59, and they placed first in the National League; they lost in the World Series to the New York Yankees.
Most of the starting pitchers remain the same; Bill Sherdel, Grover Alexander, Jesse Haines, and Clarence Mitchell remain, and Hal Haid, Syd Johnson, and others are still in the bullpen. The main difference between 1928 and 1929 isn't the personnel but rather the performances. The team ERA was 3.38, and only Flint Reim of the starting staff had an ERA greater than 4.00 (4.14). The veteran pitchers on this year's team went out and did their job, unlike in 1929.