Conversation so far:
How was Bill James connected to the Dowd Report?
In his Baseball Book 1990, Bill James heavily criticized the Dowd Report's methodology, which was an investigation (commissioned by baseball commissioner Bart Giamatti) on the gambling activities of Pete Rose.
What was the Dowd Report?
The Dowd Report is the document describing the transgressions of baseball player and manager Pete Rose in betting on baseball, which precipitated his agreement to a lifetime suspension.
How did Bill James criticize the methodology of the Dowd Report?
Bill James wrote I would characterize the evidence that Rose bet on baseball as...well, not quite non-existent. It is extremely weak.“

Question: What was the case against him?
Self-contained rewrite: What was the case against Pete Rose?