I lost some respect for Ken Burns because of his coverage of Ty Cobb (and the failure to mention the impact Bing Crosby had in bringing Jazz to white people in that documentary). Neither Burns or his staff did proper research. They relied on Al Stump, who wrote two books of lies about Cobb, and has since been widely discredited. The second Stump book which the movie Cobb was based on was mostly fiction. I knew that the second I read that book because there was absolutely no attribution for any of the stories, not to mention that Cobb's health in later years would have precluded many of those tales. And if any of it was true, why weren't there any newspaper reports about him killing people or shooting up casinos in Las Vegas? News like that would have certainly made the papers at the time.
I suggest reading this book: Ty Cobb: A Terrible Beauty.
Here's an article that Leerhsen wrote:
https://imprimis.hillsdale.edu/who-was-ty-cobb-the-history-we-know-thats-wrong/
I have noticed that Burns shades his documentaries with a political and social bias, and by doing that, occasionally leaves out things that would make some of what he does more complete. Painting Cobb as a racist who did physical harm to blacks fits Burns' thinking so he didn't bother to see what was true and what was not. When those stories were heavily researched in later years, it turns out those encounters were with white people and not black people. Burns fails to mention that the reason only four of Cobb's old teammates went to his funeral was because it was a private ceremony, and only those men were invited. Burns did not mention that thousands of people waited outside the church paying their last respects to Cobb. Burns did not mention that Cobb secretely gave financial help to old teammates. Burns did not mention that Cobb set up a scholarship foundation that helped blacks as well as whites. Burns did not mention that Cobb came from a family of abolitionists either. I could go on and on, but you get the message.
As a comic book historian for over twenty-five years who has written hundreds of biographies, I know the importance of checking bias at the door. You research, ask questions, listen to the answers, and don't leave out what doesn't fit a personal agenda.