British illusionist Derren Brown made a documentary about this, called &quot;The System&quot;, where he wrote letters to people predicting the outcome of horse races using his secret system, and suggesting they place a bet.<p>He sent different predictions to different people, some saw his predictions come true, and he sent more letters to all those people. And then repeated that, eventually narrowing it down to one person, who saw week after week correct gambling predictions, and really believed he had a system for winning.<p>She borrowed family money to bet big - then he revealed that she was the result of survivor bias and he had no system.<p><a href="http:&#x2F;&#x2F;topdocumentaryfilms.com&#x2F;derren-brown-the-system&#x2F;" rel="nofollow">http:&#x2F;&#x2F;topdocumentaryfilms.com&#x2F;derren-brown-the-system&#x2F;</a>