After the knight shift, Sir Alastair Cook believes England could hit the magic 500 mark at the World Cup. To launch the tournament’s 100-day countdown in Trafalgar Square, the former St Paul’s choirboy held court under cobalt blue skies and delivered the forecast for Eoin Morgan’s one-day side in high summer: Reign in all arias. Although Cook won a record 161 England Test caps, he never played at a World Cup – an incongruous kink in his international record. In 2011, after stockpiling 766 runs on Ashes duty in Australia, he found himself surplus to requirements, running in the ‘Triangle’ – a wooded assault course near mentor Graham Gooch’s home. Instead of opening the batting at the World Cup, Cook was flogging himself in pitch darkness at 6am, carrying bricks in a rucksack as Gooch followed on his bike, while England fell woefully short in Sri Lanka. And four years ago, Cook was axed as one-day captain just seven weeks before the tournament, with Morgan handed a hospital pass to preside over another dismal blow-out. But Lord Nelson, gazing down from his vantage point, would agree that this time the signs are all positive and England expects their one-day record…