Former South African star Herschelle Gibbs has said the mental frailties that led to his country being labelled the chokers of world cricket will not stop them from comfortably defeating Australia in next month's Test series and retaining the No.1 world ranking. Australia's chances have improved since the Ashes failure of two years ago, but Gibbs believes Michael Clarke's team will receive a reality check in the form of a 2-0 defeat.