Helenio Herrera

Helenio Herrera's Grande Inter — winning back-to-back European Cups in 1964 and 1965 — set a defensive standard that no manager before or since has matched in Serie A. His 1964–65 side conceded only 20 goals in 30 matches, a 0.67 goals-against average that is 40% lower than the typical champion's defensive record of the era. Herrera's catenaccio system outperformed Brian Clough's more pragmatic approach (ranked #6) in pure defensive efficiency, as Inter kept 14 clean sheets in that league campaign. He was also the highest-paid manager globally, earning £15,000 annually — triple the average top-division salary — and pioneered psychological techniques like team meetings and tactical drills that modern managers such as Jürgen Klopp (ranked #7) now treat as standard. Concrete data: Herrera's Inter won three Serie A titles in five seasons, a 60% win rate in domestic competitions.