The Amazing Lottery

Stats observation of the day -- After every lottery you can say, "That number had only 1 chance in 175 million of coming up!". But, there's a 100% chance you can say that, every time it's run. It's only interesting or significant if you can predict the result in advance. Otherwise you have a fallacy called "data dredging": http://en.wikipedia.org/wiki/Data_dredging

See also:

• Testing hypotheses suggested by the data
  
• Multiple comparisons fallacy
• Prosecutor's fallacy
• Ecological fallacy

Other probabilistic fallacies.