From Baseball-Reference.com:

Judge Landis begins a three-day public hearing to investigate the allegation the Detroit Tigers threw a four-game series to the Chicago White Sox in 1917. The White Sox, Swede Risberg contends, returned the favor for two games in 1919. Near the end of the 1917 season, some Chicago players contributed about $45 each to reward Detroit pitchers for winning their last series against the Boston Red Sox, helping Chicago clinch the pennant. No witnesses confirm any part of the story, although Tigers pitcher Bill James denies ever receiving any money, and the others named deny all charges. A week after the hearing opens, Landis clears all the accused, ruling lack of evidence of anything except the practice of players paying another team for winning.