Does Federer choke? To legions of tennis fans, this question about the Wimbledon number one seed’s temperament will seem absurd, akin to asking if Hillary Clinton lacks tenacity. Yet twice in finals during the clay court season this summer in Monte Carlo and Hamburg, he has surrendered large leads to his rival Rafael Nadal. By the time of the French Open this month, the Spaniard’s mental domination of his Swiss rival was so complete that a pale imposter showed up in the final. Nadal won 6-1 6-3 6-0.

Champions, business leaders and politicians live under the harshest of spotlights, their every stumble analysed for days. Gordon Brown had a last-minute loss of nerve when he decided not to seek an early election last year, Margaret Thatcher didn’t after the IRA bombing at the Conservative party conference in Brighton in 1984.