Which baseball team's cap did actor Tom Selleck wear in the TV series "Magnum, P.I."?

Tom Selleck (and his mustache) rose to fame on the CBS crime drama "Magnum, P. I." For eight seasons from 1980 to 1988, Selleck played the title role of Thomas Magnum, a private investigator based in Oahu, Hawaii.

Throughout the series, Magnum was frequently seen wearing a baseball cap, and usually it was a dark blue cap with the Detroit Tigers logo. But why was a Hawaiian P. I. wearing the cap of a team from Detroit?

Technically, it was because of the character's backstory, which indicated that Thomas Sullivan Magnum III was born in the Detroit, Michigan, area. But that backstory didn't come out of nowhere, and it wasn't the sole invention of the show's writers.

The roots of Thomas Magnum's fictional Detroit background and Tigers fandom are in the real-life story of the man who played him. Selleck was born in Detroit in 1945 and grew up watching great Tigers teams and iconic Tigers players, including Al Kaline. He's a die-hard Tigers fan and has often found ways to sneak his fandom into his work as an actor. It was Selleck, in fact, who convinced Magnum, P. I.'s writers and directors to let him wear his Tigers hat on camera, and to incorporate references to the Tigers and Magnum's Detroit roots. (There was even an episode called "Tigers Fan" in season 8.)

When CBS rebooted "Magnum P. I." in 2018, the new series paid tribute to the original by having star Jay Hernandez don a Tigers cap in the very first episode.