On December 21, 1926, Judge Kenesaw Mountain Landis dismissed a claim by Dutch Leonard alleging that Ty Cobb and Tris Speaker bet on a fixed game six years previous. The commissioner declared the matter closed, clearing both Speaker and Cobb of any wrongdoing when Leonard did not show up at a hearing to defend his accusations.
I am fuzzy on the details, and I don’t have the heart to bury myself in the search, but I gather there has been evidence which has come to light which casts some doubts on Cobb and Speaker’s innoncence.
This article discusses the matter pretty well: https://www.vintagedetroit.com/gambling-scandal-nearly-scarred-the-accomplishments-of-ty-cobb-and-tris-speaker/. From the sounds of it, the decision was ultimately based on Landis’s dislike of Dutch Leonard.