Why did Cardinals crowds shrink?

The question, and the suspects

One question: why did Cardinals crowds fall from 43,000 a game to 28,000? It began as three competing explanations and grew, as the data answered back, into five. Each gets a part of this notebook that opens with a hypothesis, a claim written so the data could prove it wrong, and each section inside it states the smaller claim it tests:

The losing. Attendance follows the team's record, with a one-year lag because season tickets are bought on last year's team. If that is the whole story, the Cardinals' drop is what any team with their recent record would have seen.
The Midwest. Mid-size Midwestern markets are losing baseball crowds regardless of wins: fewer people, older people, less to spend. If so, the Cardinals' peers fell with them.
The price. Going to a game has outrun wages, in St. Louis more than elsewhere.
The fans, and where they watch. Baseball's audience is ageing out of the stands, or has moved to the television.
St. Louis itself. The Cardinals drew far more than their record justified for decades ("best fans in baseball"), and that premium is what is disappearing: the owners, the payroll cut, the 2025 boycott, a new soccer club across town. If so, the Cardinals fell further than wins, region, price and age can explain.

The last part asks whether the fans come back, from what happened to teams like them. Before any of that, the data is loaded and cleaned with every decision logged, and the fall itself is drawn. The closing section says which hypotheses survived. Data as of 5 September 2026; the 2026 season is in progress and its numbers move with every home game. Technical terms are in bold with a plain explanation the first time they appear, and again in the glossary at the end.