In 1978, sports reporter and columnist Leonard Koppett mocked the causation-correlation confusion by wryly suggesting that Super Bowl outcomes could predict the stock market. It backfired: Not only did people believe him, but it worked -- with frightful frequency.
The proposal went as follows: If one of the 16 original National Football League teams -- those in existence before the NFL's 1966 merger with the American Football League -- won the Super Bowl, the stock market would close higher that following year than it did the preceding Dec. 31. If a former AFL team won, it would go down [sources: Koppett; Koppett; Koppett; Koppett; Zweig].
From 1967 to 1978, Koppett's system went 12 for 12; up through 1997, it boasted a 95 percent success rate. It stumbled in 1998 and 1999, when AFL alums the Denver Broncos won and the market went up [sources: Koppett; Koppett; Koppett; Koppett].
Some have argued that the pattern exists, driven by belief; it works, they say, because investors believe it does, or because they believe that other investors believe it. This notion, though clever in a regressive sort of way, hardly explains the 12 years of successful correlations predating Koppett's article. Others argue that a more relevant pattern lies in the stock market's large-scale upward trend, barring some short-term major and minor fluctuations, and the fact that an original NFL team won every Super Bowl from 1984 to 1998 [source: Norris].