How the 2014 Red Sox gave him #50
Markus ‘Mookie’ Betts was drafted by the Boston Red Sox in the 5th round of the 2011 MLB Draft. He spent three seasons in the Red Sox minor-league system before being called up to Boston on June 29, 2014. The Red Sox were short on jersey-number availability in their roster — most low numbers and most popular outfielder numbers were taken by veterans. Betts was assigned #50 — an arbitrary clubhouse number that wasn’t being used.
Betts had worn #7 in college at Vanderbilt and various numbers in the minors. After his Boston debut he kept #50 through every promotion — including 2018 when he won the AL MVP, the AL batting title (.346), an AL Silver Slugger, an AL Gold Glove, the Hank Aaron Award, the World Series with the Red Sox, and the AL pennant. He was the first AL player ever to win the MVP, the batting title, a Gold Glove, and a Silver Slugger in the same season.
Trade to the Dodgers, kept #50
On February 10, 2020, the Red Sox traded Mookie Betts and David Price to the Los Angeles Dodgers for Alex Verdugo, Jeter Downs, and Connor Wong. The trade was driven primarily by the Red Sox’ goal to reset their luxury-tax position before Betts entered free agency. The Dodgers gave him #50 immediately — the number was available (Hyun-jin Ryu had vacated it after 2019 free agency) and matched what Mookie had worn in Boston.
Betts won the 2020 World Series with the Dodgers (the COVID-shortened 60-game season followed by a 11-day postseason). He won the 2024 World Series with the Dodgers — making him a 3-time champion (Boston 2018, LA 2020, LA 2024). His #50 has worn the Dodgers blue for 6 seasons and counting — the longest-serving #50 in Dodgers history.
Other notable #50s in MLB
Sid Bream (Pirates/Braves, 1985-94) wore #50 — most-famous for sliding home with the winning run in the 1992 NLCS Game 7 against the Pirates. J.J. Putz (closer, 2003-13) wore #50 with multiple teams. Charlie Hough (knuckleball pitcher, 1970-94) wore #49 mostly but #50 in stints. Adam Wainwright wore #50 with the Cardinals from 2005-23 — his entire MLB career.
In the AL, Betts is one of two notable modern #50s; the other is Charlie Morton (briefly with the Astros). The number has historically been seen as a ‘pitcher’s number’ (rotation veterans, closers) — Betts is one of the very few elite position players to wear it. He’s now the leading career hitter ever to wear #50 (over 2,000 hits, 250+ HRs, .298 career average through 2025).
More in The Stories Behind Iconic Jersey Numbers
Wayne Gretzky 99: The Story Behind the Number Why Aaron Judge Wears #99 — A Spring-Training Default Why Allen Iverson Wore #3 — Bethel High Roots Why Derek Jeter Wore #2 — A Yankees Last Single-DigitBackground facts cross-referenced with the Wikipedia article on Mookie Betts and Pro-Football-Reference / Basketball-Reference public records.