That is why he is confident the All Whites will perform well in their first World Cup appearance in 28 years, against Slovakia in Rustenburg, South Africa, tonight (NZ time).
Technically, the 83-year-old Dunedin man has a foot in both camps.
He was born and raised Jaroslav Sigmund in the former Czechoslovakia, before fleeing the communist country in 1948 and arriving in New Zealand in 1951.
But Mr Sigmund is a proud All Whites fan and the No 1 supporter of his grandson, New Zealand defender Ben Sigmund.
"I have to pick the All Whites. I really hope they can do it and there is no reason they can't win," Mr Sigmund said yesterday.
"Ben is a good boy, a very solid player. We talked on the phone just on Saturday.
"He complained a bit that he had lost weight because they have been working so hard. But he is very excited."
The younger Sigmund was raised mainly in Christchurch, where his parents, Tony and Ngaire, who have gone to South Africa for the World Cup, still live.
Jerry Sigmund has lived in Dunedin since 1957.
His second wife, Bev, died last year, but other Sigmunds still in the city include his son and daughter-in law, Pete and Rach, and two grandchildren (Ben's cousins), Josef (10) and Paige (7).
The Sigmund clan is noted for a feisty, almost rebellious streak.
Ben shows that on the field and it can be traced back to his grandfather's life story.
Mr Sigmund, a Czech whose father was in the textile trade and mother worked in a bicycle factory, had gone into the grocery business upon leaving school in Czechoslovakia.
In 1944, he tried to join the partisans rising up against the pro-Nazi regime but was arrested and detained in various camps for political prisoners.
Awaiting trial, Mr Sigmund walked free when the country was liberated in May 1945.
He decided to leave his country after the communist coup in February 1948 - he still has the original train tickets from his departure, and vivid memories of skiing over a mountain range into Germany - had a spell in the Foreign Legion, and then worked in the immigration office of the International Refugee Organisation in Italy.
"My boss there asked if I wanted to immigrate, and my choices were Canada, Australia or New Zealand," Mr Sigmund recalled.
"She said she had heard New Zealand was a nice place, so here I am."
Mr Sigmund worked on the Roxburgh hydro project and then as a rabbiter near Queenstown, before working at the Roslyn woollen mill until his retirement.
He played football and did athletics and gymnastics in his youth, and now plays indoor bowls "with a steel knee and a new hip".
