In the old days, the greatness of an All Blacks coach and his side was determined by a series win over South Africa or the Lions (Australia were easy beats), or a run of crushing victories on European tours.
Today, winning the World Cup is the key measurement of success.
Foster’s side — with their backs to the wall and some dazzling players in their ranks — are capable of defying the sceptics. Come the end of October, he could be holding the Webb Ellis Cup.
Through the other sliding door: Lose the opening match against hosts France then get dumped in the quarter-finals by the Springboks or Ireland, and his tenure in charge of world sport’s most successful team would be regarded as dismal.
Regardless, he should get the chance to prove himself. The decision on who coaches the All Blacks after the World Cup should be made after the World Cup.
Back in August, the Herald rightly called for Foster to go — we backed Scott Robertson, and still firmly believe that appointing the Crusaders boss would have been the right move.
But after his men scrambled to an epic victory in Johannesburg, NZ Rugby stuck with their embattled coach, backing him to stay in the role until the World Cup campaign is complete.
They backed Foster then, and he deserves their confidence and certainty now.
They can do that by setting the appointment process after any tournament review.
NZ Rugby should let Foster have an unclouded run into the tournament, or else risk finding themselves in the absurd position of having egg on their faces as their man lifts the trophy.