Let’s start by blaming the parents. When the infant Bjorn Borg threw a tantrum at his local tennis club, his parents Margarethe and Rune locked his rackets up in a cupboard for a few weeks; Bjorn didn’t thereafter misbehave. Kay and John McEnroe Senior never tried this tactic on John Junior, perhaps fearing that the boy might respond by dynamiting the cupboard. The young McEnroe was a shy child, who preferred – and was allowed – to skulk in his room with a hamburger when his parents had company for dinner; this resulted in appalling table manners and a general lack of social graces. ‘We were rookies at the parent job,’ John Senior offers in his defence, ‘but we got better at it.’ For the record, Margarethe and Rune Borg were also rookies at the parent job, Bjorn being their only child.