From Wikipedia.
San Diego has the largest championship drought in the nation with at least two major-league sports franchises; dating back to 1963 (47 Years as of 2010), as well as being the largest United States city to
have not won a Super Bowl, World Series, Stanley Cup, NBA Finals or any other Major League sports championship. Some fans believe that there is a curse on the major league teams in the city.
https://en.wikipedia.org/wiki/Sports_in_San_Diego