2. Firing Mike Shildt
Back in September of 2021, the Cardinals were mired in third place in the NL Central and were 3.5 games back in the Wild Card race. But on September 10, a comeback against the Reds sparked a historic surge.
St. Louis won a franchise-record 17 consecutive games and ultimately cruised into the second Wild Card spot. They lost to the Dodgers in a hard-fought Wild Card game, but the 17-game win streak brought joy to the City of St. Louis.
The following week, they made one of their biggest mistakes in recent history, and fired then-manager Mike Shildt over what was described as a "philosophical difference." Oli Marmol was promoted to replace Shildt.
However, Marmol is a very analytically driven manager, which isn't a bad thing, but analytics appear to play a key role in his managerial decisions, and an over-reliance on them can lead to trouble, as it did in 2023.
Shildt later revealed that he was fired after sharing his opinion on a few things and how he thought the Cardinals could improve, which made it clear that the front office wanted a manager who didn't question anything, which Marmol doesn't seem to do.
This year, the Cardinals' bullpen and defense, which were strengths in 2022 fell apart and contributed heavily to their downfall.
Shildt's primary focus as manager of the Cardinals and a disciple of George Kissel himself was sound fundamentals. The Cardinals were severely lacking in that regard during the turbulent 2023 season.