Welcome back to our 30 for 30 documentary short series.

President Franklin Delano Roosevelt once told the head of the Office of Strategic Services (precursor to the CIA), “Give my regards to the catcher.” The catcher was Moe Berg, who spent 15 seasons in the majors before taking up espionage for the government. Spyball tells the extraordinary story of Berg, a linguist/Ivy-educated lawyer/.243 lifetime hitter whom manager Casey Stengel called “the strangest man to ever play the game of baseball.” Berg walked in eclectic circles, counting Babe Ruth, Albert Einstein, and the Marx Brothers among his friends, but it was his service to his country that truly distinguished him. His surreptitious filming of Tokyo during a 1934 baseball tour helped develop strategies for the eventual bombing of the city during World War II, and his cloak-and-dagger mind games involving a German scientist helped prove that the Nazis were failing in their attempts to develop an atomic bomb.

Recent 30 for 30 Shorts

• Ted Turner’s Greatest Race, directed by Gary Jobson »

• The Anti-Mascot, directed by Colin Hanks »

• Unhittable: Sidd Finch and the Tibetan Fastball, directed by Peter Sillen »

• The Billion-Dollar Game, directed by Nick Guthe »