There are various origin stories to the gesture, but the most widely accepted one pins the high five to a 1977 baseball game between the Los Angeles Dodgers and the Houston Astros. It was the last game of the season, and Dodgers outfielder Dusty Baker had just hit a home run — his 30th of the season. The accomplishment made the Dodgers the first team in Major League history to have four players hit 30 homers.