When did Baseball players start wearing numbers regularly?

There had been a couple of attempts to use numbers in the major leagues before the idea caught on. In 1916, and again in 1917, the Cleveland Indians experimented with numbers on their sleeves, as did the Cardinals in 1923. On January 22, 1929, the Yankees became the first team to use numbers regularly, thinking that fans could recognize players more easily that way. Initially, players were given numbers based on the batting order - for example, Babe Ruth batted third, so he wore No. 3. It took until 1937, however, for every team to have their numbers on all their shirts - the last to change being the home uniforms for the Philadelphia A's.