During his time with the All Blacks from 1985 to 1993, he wore the number 10 jersey (first five-eighth or fly-half), and was the main goalkicker for the All Blacks. He amassed 645 points from 46 All Black Test Matches (1 try, 118 conversions, 128 penalties, 7 drop goals). He is considered a true pioneer of the modern art of goal kicking, in particular the technicalities of leaning the ball forward, which has been adopted by world class kickers since. Many believe he is one of the greatest first five-eighths in All Black history, even though he was not a great runner with the ball in hand.
Despite his relatively short height, he made up for this with fantastic distribution skills reinforced by his long-term colleague John Kirwan's then-world-record career statistics playing outside him for Auckland and the All Blacks. His inability to score tries was often a joking point in the team – his cause not helped by an overruled attempt against Ireland in 1989 (due to a prior technical infringement by a teammate).
The highlight of Fox's career was winning the inaugural Rugby World Cup with New Zealand in 1987, a victory based in part on his accurate kicking.