the Great, King of Prussia from 1740 to 1786, "put together his armies as a well-oiled clockwork mechanism whose components were robot-like warriors. No individual initiative was allowed to Frederick's soldiers; their only role was to cooperate in the creation of walls of projectiles through synchronized firepower." This was in the pursuit of a more effective army, and such practices made it easier to look at war from a top-down perspective. Disciplined troops should respond predictably, allowing study to be confined to maneuvers and command. Prussia's victory over the Second French Empire in the Franco-Prussian War (1870–71) is sometimes partly credited to the training of Prussian officers with the wargame Kriegsspiel, which was invented around 1811 and gained popularity with many officers in the Prussian army. These first wargames were played with dice which represented "friction", or the intrusion of less than ideal circumstances during a real war (including morale, meteorology, the fog of war, etc.). 21st century militaries still use wargames to simulate future wars and model their reaction. According to Manuel de Landa, after World War II the Command, Control and Communications (C3) was transferred from the military staff to the RAND Corporation, the first think tank. Around the mid to late 20th century, computer simulated war games were created to replace traditional war gaming methods with the goal of optimizing and speeding up the process and making it possible to analyze more complex scenarios with greater ease. In 1958, the Naval War college installed a computer war game system where their traditional war gaming activities were held. The system was called the Navy Electronic Warfare System, and cost over $10 million to install. The change from traditional war gaming methods to electronic computer simulated ones meant that the value and accuracy of a war game simulation was less dependent on skill and individual experiences, and more dependent on quantitative data and complicated analysis methods. Von Neumann was employed by the RAND Corporation, and his game theory was used in wargames to model nuclear dissuasion during the Cold War. Thus, the U.S. nuclear strategy was defined using wargames, "SAM" representing the U.S. and "IVAN" representing the Soviet Union. Early game theory included only zero-sum games, which means that when one player won, the other automatically lost. The prisoner's dilemma, which models the situation of two prisoners in which each one is given the choice to betray or not