By ADAM HATHAWAY

Jack van Poortvliet insists England’s dismal Six Nations will help him cope with the furnace of the upcoming World Cup as Steve Borthwick’s side seek to defy recent form.
Still just 22, the Leicester scrum-half was on the wrong end of three defeats out of five in the spring as Borthwick’s men slumped to fourth in the table.
Van Poortvliet started all five kicking off with a 29-23 home hijacking by Scotland, a five-try beating of Italy and a nail-biting 20-10 defeat of Wales.
Then England were hammered 53-10 at Twickenham by a rampant French side before losing 29-16 in Dubl...