In the 1942 classic The Pride of the Yankees, Gary Cooper was tasked with bringing to life the legendary Lou Gehrig, who had retired just three years before and died one year earlier from the disease that bears his name. The only problem: Cooper was righthanded and Gehrig was a lefty. For 70 years, the story has been that the filmmakers solved this problem not by having Cooper bat righthanded and hope no one would notice because that would be completely ridiculous (oh, wait), but instead by filming Cooper doing everything righthanded and then flipping the film in post-production so that it appeared he was a lefty.
If this seems like an awfully convoluted way to get around the issue, perhaps we can interest you in more than 5,000 words of painstaking detail as to what really happened, complete with appearances by a Yankees Hall of Fame catcher (not that one) and his wife, the truth about Wally Pipp, dialogue from Casablanca (not that one) and a fire insurance map of Wrigley Field (not that one). Tom Shieber at the blog Baseball Researcher has done an incredible job. Using approximately 50 stills from the movie, some backstory as to working Hollywood practices and information about men's clothing vs. women's clothing, he appears to have settled this question once and for all.
After reading this you may not even want to see the movie, though you should. It cemented Gehrig's place in the American consciousness and helped turn his farewell speech into baseball's version of the Gettysburg Address. It even won an Academy Award. The category? Film editing.-- By Ted Keith