Mookie Betts has been one of MLB‘s top players for a while now. Even before joining the Los Angeles Dodgers and winning a World Series in 2020, he’d enjoyed a successful career with the Boston Red Sox, earning his first career championship and the 2018 American League MVP.

Betts and his No. 50 uniform have become widely known throughout the world of baseball, but Mookie isn’t actually his real name. How’s that for a fun piece of trivia?

Mookie is not his real name, so what is it?

Many people may know him as Mookie Betts, but that is not his real name.

On Oct. 7, 1992, Betts was born to Diana Collins and Willie Betts, who divorced while he was in elementary school, and his legal name is Markus Lynn Betts. His parents chose his name, at least in part, so that his initials — MLB — would match those of Major League Baseball. The sport ran in the family, and Terry Shumpert, a 14-year MLB veteran, is his first cousin once removed.

“I guess my parents were watching Mookie Blaylock play basketball, and it was right after I was born,” Betts told CSNNE.com about the nickname in July 2013. “They were watching him play, and they gave me the name right after that. I’ve never met him. I haven’t met either Mookie — Blaylock or Wilson. I’ve only even heard of maybe one or two other people named Mookie, but I’ve never met anybody.”

It’s unknown whether Betts and Blaylock have since crossed paths.

Betts is the only player named Markus to appear in an MLB game, though multiple players by the name have populated the minor leagues. He and Mookie Wilson remain the only two players in league history to go by his widely-known moniker.

Is Mookie Betts the most successful Mookie in the Big Four American sports?

Heading into the 2023 MLB season, Mookie Betts had tallied 56.2 WAR, leaving him just outside the top 200 in the league’s lengthy history, per Baseball Reference. For the sake of comparison, Mookie Wilson, who spent 12 seasons roaming centerfield for the New York Mets and Toronto Blue Jays, accumulated just 22.3 WAR.

Betts clearly has the baseball title, but what if we expand the search to include the other major men’s American sports leagues: the NBA, NFL, and NHL?

The NBA is the obvious place to start given the prominence of Mookie Blaylock, and the 6-foot-0 point guard is the only player in the Association’s history to lay claim to the name.

Though it’s by no means a perfect measure, we can use win shares as an all-in-one barometer of Blaylock’s success with the New Jersey Nets, Atlanta Hawks (for whom he made his lone All-Star appearance), and Golden State Warriors. With 71.8 win shares in his 13-year career, Blaylock sits at No. 212 on the all-time pecking order, per Basketball Reference.

To date, no one named Mookie — whether legally or practically — has suited up in the NHL or NFL, so this becomes a two-man competition between Betts and his self-proclaimed namesake.

Betts already has the slight edge, at least by the chosen metrics, and he’s only 30 years old. By the time. he hangs up the cleats, the contest for name supremacy may well be a foregone conclusion.