Red or Blue

It turns out that in the 2005 study, the authors wrongly assumed red jackets were randomly assigned to Olympic athletes However, Seife found that,  in the Olympics, an athlete's position within the (competitor's brackets) determines the uniform color that he wears in each round of the competition. In many tournaments, athletes are placed so that the best competitors, as determined by preliminary rounds or by another form of ranking, are unlikely to face each other in early rounds of the competition. This arrangement is not strictly random; thus, it potentially creates a bias toward one color or another. In fact, blue-jackets won more often in some 2008 Olympics wrestling competitions because of the distribution of blue jackets to winners of early rounds.

The original red versus blue study was a good example of one class of errors that come from misunderstanding randomness by seeing a pattern when there was really none to see, and assume that something is purely random when it is not.