Heads or tails is a simple game, which consists of throwing a coin into the air to then check which side of it is facing up after it has fallen. It is commonly used to choose between two alternatives or to resolve a dispute between two parties. This method of choice necessarily has only two possibilities of 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, the coin decides who will have the right to choose the field or the ball.
Heads or tails was already important to resolve major impasses: in the USA, in 1845, Asa Lovejoy and Francis Pettygrove threw the coin to find out who would choose the name of the new city in the state of Oregon. Pettygrove won and named the city Portland.