Playing cupid

Especially for Valentine's Day, Game Theory expert Dr Nicos Georgiou looks into the mathematics of dating. In the 2001 biopic A Beautiful Mind mathematician John Nash (played by Russell Crowe) devises a dating strategy for his friends. Although they all fancy "the blonde" in a group of women, he points out that none of them will get her because they'll end up blocking each other. And if they then turn to her friends, they'll be rejected because no one likes to be second best. So the solution is for his friends to approach the blonde's friends first. Known as Nash's Equilibrium, it illustrates that the best result comes from everyone in the group doing what's best for him/herself and the group. Nash's Equilibrium is a central application of game theory, which uses mathematical modelling to understand the decisions individuals make and how these decisions affect groups.