Heads or Tails is a simple game, which consists in throwing a coin to then check which of its sides was turned up after his fall. It is commonly used to choose between two alternatives or to resolve a dispute between two parties. This method of choice necessarily have only two possibilities result, which have the same probability of occurrence. A frequent use is the decision of who will make the initial move in some activity. In football, for example, money decides who will have the right to choose the field or the ball.