Ironically, first aired in the fall of 1994 when much of the season and the World Series were cancelled due to a strike. This made it the only "baseball" available to millions of unhappy fans at what should have been the most exciting time of the season.
When working on the original series of films the producer wondered if they should keep in the statement that the Red Sox would never again win the world series, they decided to keep it in, despite this being the favorite team of filmmaker Ken Burns. Then in 2004, the team won the world series. As a result, Burns decided to add a "tenth inning", updating things in a number of ways, including the strike and permanent resolution, the steroids scandal and other aspects of recent baseball history.
When discussing Yogi Berra's many interesting quotes, a friend of Yogi's is alleged to have said, "Hey, Yogi, what do you know?" Yogi allegedly replied, "I don't even suspect anything." This exchange is actually taken from an exchange Charles Chaplin had in a Parisienne café in Monsieur Verdoux (1947).
The series is structured in baseball fashion: divided into "innings", each with a top and bottom half; opens with the national anthem; is given "play by play" by the narrator along with "color commentary" by various experts; eventually goes to extra innings; etc.
When Bill "Spaceman" Lee is interviewed and quoted at various times during the series, he is wearing a red baseball cap with "CCCP" on the front in gold letters. "CCCP" is the Cyrillic (Russian) lettering for "USSR", the Union of Soviet Socialist Republics, the former Soviet Union.