Today, April 16, marks the 90th anniversary of a big development in baseball uniform history – the wearing of numbers on the back of a team’s jerseys for the first time.

While much of the conventional wisdom has it that the New York Yankees were the first team to carry numbers in Major League Baseball, it’s not actually true. It is correct that the Yankees announced in January 1929 that their players would have numbers on their backs for the coming season, beginning in April – however, their scheduled opener with the Boston Red Sox at Yankee Stadium on April 16 was rained off, as was the following day’s play against the Sox.

In early 1929, the Cleveland Indians also announced plans to carry jersey numbers and so – fittingly, given that they had experimented with sleeve numbers for a few games in 1916 – they created history in their matchup with the Detroit Tigers.

Both the Indians and the Yankees numbered their teams according to batting order, 1-8, with backup catchers given 9 and 11 (the latter, Grover Hartley, was also a coach and his fellow coach Howie Shanks wore 10). Pitchers were 12 upwards.

When fielding, this is how the historic Indians looked: 1. Jackie Tavener (shortstop), 2. Carl Lind (second base), 3. Dick Porter (right field), 4. Joe Sewell (third base), 5. Earl Averill (centre field), 6. Lew Fonseca (first base), 7. Charlie Jamieson (left field), 8. Luke Sewell (catcher) and 12. Joe Shaute (pitcher).

Two days later, the Yankees finally got to premiere their numbers. Like the Indians, their starting batting order was 1-8, their backup catchers wore 9 and 10 and pitchers 11-21 inclusive (though, like football when a second substitute was allowed in the 1980s, number 13 was omitted).

Their fielding format: 1. Earle Combes (centre field), 2. Mark Koeing (third base), 3. George Herman ‘Babe’ Ruth (right field), 4. Lou Gehrig (first base), 5. Bob Meusel (left field), 6. Tony Lazzeri (second base), 7. Leo Durocher (shortstop), 8. Johnny Grabowski (catcher) and 14. George Pipgras (pitcher).

Their number 10, Bill Dickey, became starting catcher and he was rewarded with the number 8 the following year, but he was more the exception rather than the rule in terms of ‘trading down’ to single digits. The reasons for this were players becoming attached to higher number they were were given, and the reduction in available low numbers as the Yankees began the practice of retiring numbers.

The first instance of this was in 1939, when Lou Gehrig had to retire after he was diagnosed with amyotrophic lateral sclerosis or motor neuron disease, which came to be known as Lou Gehrig’s disease. Babe Ruth’s number 3, Joe DiMaggio’s number 5 and Mickey Mantle’s number 7 were retired in 1948, 1952 and 1969 respectively and nowadays the Yankees have none of the numbers 1-10 available, following the retirement of number 2 in honour of Derek Jeter in 2017. However, earlier this year, pitcher Adam Ottavino created history as the first Yankee to wear 0.

For their opening game against the Baltimore Orioles in 2019, this is how the Yankees fielded. Incidentally, right fielder Aaron Judge is an outlier in wearing 99 as few players have numbers above 60.

In total, the Yankees have 21 retired numbers, the most in MLB, while neither they nor any other team can assign the number 42 since 1997. This was retired across the all teams in honour of Jackie Robinson, the first African-American to play the sport at the top level (though players wearing 42 at the time could retain it). Since 2004, April 15 has been adopted as Jackie Robinson Day, with every player wearing 42 on that day.

The meeting of the Yankees and the Indians in May 1929 was the first where both teams wore numbers and other club began to follow their lead. In 1937 the Philadelphia Athletics became the last team to adopt them. In 1939, the Cincinnati Reds started a tradition where catchers, coaches and managers wore single digits, infielders 10-19, outfielders 20-29 and pitchers 30-39. Other teams followed suit, though there were never any formal rules applied.

In 1960, the Chicago White Sox became the first team to wear names above their numbers and this practice quickly gained traction too – some teams only did for their away jerseys, expecting a home crowd to know their players by number only. The Yankees held out, though, and it wasn’t until the 2017 Players’ Weekend initiative, where players wore nicknames on jerseys, that the numbers on their backs had company.