Recently the financially troubled General Motors Corporation started a TV ad campaign in the U.S. featuring GM workers "putting their rally caps on". Baseball fans recognize that a rally cap is a baseball cap worn inside out when your team is losing. Supposedly the rally cap brings you luck.
I first became aware of rally caps while watching New York Mets games in the 1980's. A wikipedia article specifically mentions the 1986 NY Mets wearing rally caps in the World Series. However, the wikipedia article says rally caps were invented by Detroit Tiger fans in 1942 and may have played a role in the Tigers' 1945 World Series victory. Whether inside-out caps worn in Detroit in the 1940's were called "rally caps" is not clear. I never heard of the Detroit connection and I've flagged the wikipedia article as "citation needed" for the 1942 origin.