"The Big Match," by Ivar Ekeland. Nature, 4 June 1998.
Game theory is a mathematical description of decision-making strategies. In this article in the scientific journal Nature, a famous problem from game theory and its solution are described. A zero-sum game with two players is a situation where whatever one person wins, the other must lose. Non-zero-sum games have more complicated possible outcomes, in which both players could wind up ahead of where they began, for example. Such games are more difficult to solve, and mathematicians were unsure of whether some could even be solved. The article explains that recently, the French mathematician Nicolas Vieille developed a complex proof that they all can be solved.