Arrigo Sacchi

Arrigo Sacchi never played professional football, yet he transformed AC Milan into the greatest club side in Europe between 1987 and 1991, winning back-to-back European Cups (1989, 1990), two Serie A titles, and two Intercontinental Cups. His 4-4-2 pressing system — zonal marking, high defensive line, collective pressing — was 15 years ahead of its time and is the tactical ancestor of Klopp's gegenpress and Guardiola's high block. He also led Italy to the 1994 World Cup Final. Sacchi proved football could be a purely intellectual discipline.