The Keys to the White House
The Keys to the White House, also known as the 13 keys, is a historically based prediction system for attempting to predict the outcome of contemporary presidential elections in the United States. It was developed by American historian Allan Lichtman and Russian geophysicist Vladimir Keilis-Borok in 1981, adapting methods that Keilis-Borok designed for earthquake prediction.
Source: Wikipedia — The Keys to the White House (CC BY-SA 4.0)