Two primary schoolchildren have the future of New Zealand chess at their fingertips.

During a recent five-city tour of the country, British grandmaster Nigel Short played an estimated 150 local talents, but singled out Aucklanders Bobby Cheng, 8, and Harry Ruan, 6, for praise.

It took 40 moves for one of the world's best chess players to gain a tactical advantage over Bobby.

At one point he walked up to his dad, Frank, and whispered to him that he stood a chance of winning. He didn't win, but the talent was apparent.

Bobby's coach, Bruce Wheeler, believes he has the potential to become a grandmaster - only the country's second after Wainuiomata's Murray Chandler.

"I'm a three-time club champion, and I have to be very careful when playing him," said Mr Wheeler, also the Auckland Chess Centre president.

At just 7, Bobby represented New Zealand at the World Under-10 Youth Championship in France, holding his own against children up to three years older. With age and maturity, his skills would only improve, said Mr Wheeler.

The Epsom student's talent was a chance discovery. His parents had seen an advertisement in a local Chinese newspaper, and decided to send Bobby and his 10-year-old sister, Joy, to learn chess. Joy lost interest, but Bobby's keenness only soared.

That was less than two years ago.

"In the beginning I beat him all the time, but now it's the other way around," said Mr Cheng.

Bobby plays up to 15 hours of chess a week as well as school, soccer practice and watching rugby.

"He's doing well so far, but honestly, we don't know how far he can go. And we don't want to push him," said his mother, Clare Chen.

Bobby has stiff competition in Harry and fellow Aucklander Puchen Wang, at present New Zealand chess' big hope. Puchen, 14, has already represented the country at adult level.

But it was the 6-year-old who caught Short's eye. He said Harry was far from focused during their match, yet still played admirably.

"He seemed to decide his move in three seconds, ran off to play football with his friends, and came back when it was his turn. Just incredible."

Harry learned to play only a year ago, having tagged along to brother Jack's chess classes at school.

Their mother, Nellie, said neither she nor husband Henry had any idea of his talent. Now Harry has already overtaken his 9-year-old sibling.

Both played in the national junior championships in July, where they dominated in the under-10 and under-8 category. In both categories, Harry finished first, with Jack second.

Their coach Ewen Green sums up their talent: "You pinch yourself to remind yourself that you're only playing someone who's 6 or 7 or 8."

And for Harry, the best thing about chess? He thinks for a while, then announces confidently: "Winning".