When Dan Carter reckons something isn’t quite right with a rugby ball, people listen.

So when the All Blacks’ goal kicking wizard admitted yesterday that the official Gilbert “Virtuo” ball used during the World Cup had caused some frustrations, it was time to dig up a few statistics.

And despite the International Rugby Board purring that it had received no complaints about the ball’s performance, the facts tell a more sombre story.

Of the six Tri-Nations kickers monitored by Fairfax, only South Africa’s Morne Steyn has improved his percentages – up five points to 85 per cent – with the new “Virtuo” nut used during the World Cup.

Carter percentages from Super and Tri-Nations matches have dipped from 75 to 67 during the World Cup, All Blacks team-mate Colin Slade has dropped four to 67, James O’Connor is down from 69 to 63 and Quade Cooper has slid from 67 to 50.

If the IRB is worried, it is not showing: “We are very happy with the Gilbert Virtuo Rugby World Cup 2011 match ball,” a spokesman said yesterday.

Each team, he said, was supplied with 30 balls. They were kicked prior to delivery and the only difference from the balls used during the Tri Nations was the livery.

But Carter was chirping a less convincing tune yesterday.

“Yeah, it can be [frustrating] at times, but obviously when you play with a certain ball you get used to it. And to have a new one just for such an important tournament it can be frustrating early on. But that is just a matter of getting out and working hard on the practice pitch.”

Questions were first raised about the Gilbert product when England’s Jonny Wilkinson and Argentina’s Martin Rodriguez missed 10 attempts between them in their opening-round match at the enclosed Otago Stadium.

Given Wilkinson’s reputation, it was a strange sight and although the first-five did his best not to blame the ball, his manager Martin Johnson was not subtle.

Johnson claimed the balls must have been duds to cause Wilkinson, who duffed a shot almost in front of the posts, to have such a poor night.

In reply, Gilbert’s international brand manager, Andrew Challis, defended his product and suggested the pressure could have caused the players’ poor ratios.

Gilbert has said tournament balls had been checked by their “ball engineer”.

Rarely one to complain, first five-eighth Carter noted that the World Cup ball, unlike some others, had the potential to cause kickers anxiety if they did not belt the sweet spot.

“It doesn’t have as much give,” he explained. “So obviously if you don’t quite strike it right then it doesn’t fly as straight as you would like it to at times.

“But it is the same for every kicker and it is just a matter of continuing to work on the practice pitch to make sure you’re fine-tuning your routine and rhythm.”

When asked to compare the differences between the World Cup and Tri Nations balls, Carter said the differences were subtle but could create havoc when it flew through the air.

“There are some slight changes. But it just does not have as much give for a kicker which provides its challenges but it is just one of those things you have to adapt to.”

Former All Blacks first five-eighth and kicking machine Grant Fox said he had been intrigued by the drop in percentages.

“It’s hard to judge unless you are kicking the ball – and I can’t do that anymore anyway – but if there’s something not quite right, you may have to strike it perfectly every time. That may be Dan’s frustration. If there is a slight mishit it may not do what you want.”

AT A GLANCE

How the big guns are faring:

Morne Steyn (South Africa) 17 from 20: 85 per cent
Ronan O’Gara (Ireland) 10 from 12: 83 per cent
Dimitri Yachvili (France) 7 from 9: 78 per cent
Toby Flood (England) 9 from 12: 75 per cent
Dan Carter (New Zealand) 8 from 12: 67 per cent
Colin Slade (New Zealand) 10 from 15: 67 per cent
James Hook (Wales) 6 from 9: 67 per cent
James O’Connor (Australia) 5 from 8: 63 per cent
Felipe Contepomi (Argentina) 4 from 8: 50 per cent
Quade Cooper (Australia) 4 from 8: 50 per cent
Jonny Wilkinson (England) 7 from 14: 50 per cent
Martin Rodriguez (Argentina) 8 from 17: 47 per cent
Jonathan Sexton (Ireland) 5 from 13: 38 per cent