Rock, Paper, and Scissors

Probably every one of you knows the game of rock, paper, and scissors. Can some people play the game better than others? Yes, Perhaps by picking up subtle hints from the faces and postures of their opponents. People are notoriously bad at creating actually random series. They tend to switch too often, avoiding choosing the same move two or three times in a row, for instance (which ought to occur fairly often in a genuinely random series). Knowing that your casual effort to create a genuinely patternless series is apt to fail, you should consider a better strategy: get a table of random numbers from the library (or online).

Philosopher Daniel Dennett's Book Intuition Pumps