Football as a contest of choices: penalties, tactics and the rules themselves, and what the best decision looks like when the other side is thinking too.
3 parts Intermediate
Start at part 1A penalty taker and a goalkeeper choose at almost the same moment, and any habit gets punished. Game theory says both should mix it up, and says exactly how often. The professionals turn out to do almost exactly that.
Intermediate Part 1
Keepers almost never stay put for a penalty, and takers rarely go down the middle. Add the middle to the penalty game and the maths explains both, says how often each should happen, and shows why a perfect Panenka gets used less, not more.
Intermediate Part 2
In 1982 West Germany and Austria knew a 1–0 win for West Germany put them both through, and for 80 minutes nobody tried to change it. Game theory's most famous puzzle, the prisoner's dilemma, explains why deals fall apart. Gijón shows the other kind, the deal that needs no one to agree to it.
Intermediate Part 3