It's tradition. It gives a sense of pride. And when 50,000 people do the Tomahawk Chop at Atlanta Braves games, it can be spectacular.
Most people believe that the tradition began in the early 1990's, when Deion Sanders played for the Braves. Legend has it, the chop followed him from Florida State, where he went to college.
Now it's part of the Braves identity. At Turner Field, several signs welcome fans to "Choptober."