The World Series is the first to be broadcast on radio.
The 1921 World Series featured John McGraw's New York Giants, dedicated practitioners of the dead-ball era's "inside game", and the New York Yankees, who relied on the "power game" exemplified by Babe Ruth, who was coming off of what was arguably his best year ever statistically. This was the first World Series appearance by the Yankees, who have gone on to play in the Series a record 40 times. The 1921 Series was a closely contested matchup that ended on a double play featuring a baserunning miscue. It was also the last of four World Series to use the best-of-nine format, which had been used in the 1903, 1919, and the 1920 editions. The following year, the World Series permanently switched to a best-of-seven game format where it has remained ever since.