Who is your favorite baseball player? What is his number? Before 1929, you would not be able to answer that question.
On April 16, 1929, history was made. The New York Yankees baseball team changed their uniforms. Numbers were added to the shirts. Before this day, baseball uniform shirts had just the team name.
The Yankee uniforms are white. They have blue pinstripes. There is a "NY" on the front. It stands for New York. The player number is on the back. Each player is listed in number order. The numbers come from a list. It is called a lineup. The player's number comes from his lineup number. For example, Babe Ruth's number was 3. He was the third player to bat.