It was after falling down a Himalayan crevasse and being involved in a dramatic mountain rescue with Sir Edmund Hillary, a year after Hillary's ascent of Everest, that Brian Wilkins decided to spend more time concentrating on cricket. Now he takes phone calls from Slovenia inquiring about his practical views on the flight and spin of cricket balls.

The 73-year-old New Zealander, who holds a PhD in pharmaceutical chemistry and is an honorary research fellow at Wellington's Victoria University, has spent much of his life fascinated by what controls the swing and spin of cricket balls. A devotion which began with drawings in an old exercise book while he was playing lower grade cricket has progressed to the point where he has published two books on the subject.

His caller from Slovenia was an American diplomat who first encountered cricket on a posting in Australia, started playing it and is now hoping to organise an international match between Slovenia and Bulgaria. He rates Wilkins' book The Bowler's Art as one of the three best cricket manuals ever published. The others were Don Bradman's The Art of Cricket and Mike Brearley's The Art of Captaincy.

Not bad company, but it has hardly made Wilkins a prophet in his own country. Despite his compelling research and practical use of wind tunnels to prove his theories, Wilkins has never been asked to elaborate on his findings to New Zealands Test or one-day players in the hope that it could further their bowling.

The BBC's Tomorrow's World regarded him as being sufficiently up with the play to investigate the likely effects of the controversial white Duke balls to be used in the World Cup. The New Zealand squad was sent a shipment to practise with in the weeks before leaving for England, but Wilkins telephone never rang.

His findings, after comparing three red balls with three white Duke balls, were simple: the white ball will swing 50 per cent more than a red ball.

If the experience of the New Zealand players in their familiarisation with the Duke ball is anything to go by, it will also hurt a lot more. The Duke is harder than white balls previously used in one-day matches, with a view to providing freer hitting right up to the end of each innings. Thats if the players still have anything to hit with  the ball is so hard that six bats were broken in New Zealand practice.

Using a self-made gun that works like an oversized crossbow, Wilkins and fellow enthusiast Dr Colin Cook were able to fire balls at a precise seam angle, something traditional bowling machines cannot do. "Working in the still atmosphere of the university recreation centre we fired the balls at 70mph, with the seam set at 25 degrees to the line of flight, at a soft target 53 feet away," Wilkins says. "Three balls of each colour were fired, with the balls rotated into different positions  a total of 144 firings.

The red balls swung on average about six inches, while the white balls swung about 12 inches."

The reason, says Wilkins, became clear after examining the different surfaces of the two balls. "Whereas the white balls have a glassy finish, the red retain some of the texture of the leather," he says. "This almost invisible difference illustrates how sensitive swing is to surface roughness." It also cuts to the quick of Wilkins' work  the amount of swing is dependent on the air stream around the ball and whether it leaves the surface earlier on one side of the ball than the other. The tilted seam of the ball creates a roughness which delays the airflow, while the extra shininess of the white ball lacquer makes the air leave a little earlier.

The abrasiveness of pitches, and the amount of punishment the ball gets from bats and boundary hoardings, are huge factors. Englands lush May outfields will guarantee that the shine takes longer to wear off  ideal conditions for swing bowling.

"Another interesting consequence will be the greater pace off the pitch as the smoother ball skids through without gripping," says Wilkins. "The bounce angle will be less on average but, because of the extra pace, the carry will be just as much as for a high bouncing ball which usually comes off a little slower."

The seam on the Duke balls is only half the normal height, which will not lessen the swing but rather make it more difficult for bowlers to cut the ball from the pitch or get it to kick up.

"The medium-pacers and fast bowlers are going to do very well with this ball, provided they can control the swing and not come up against the wide restrictions," says Wilkins. Reverse swing, he maintains, will not be a factor because it is generally achieved with an old ball.

Spinners, according to Wilkins, will not be happy. The almost non-existent seam, coupled with the extra shine, will affect their grip and the way the ball acts on the pitch. "Spinners might have a lean time unless they can exploit swerve, the curving flight that depends not on relative roughness of two sides but on spin."

Wilkins, who still plays in Wellington as a wily leg-spinner, became interested in his subject because, despite extensive research, he could never find a convincing explanation for what made the ball swing. "It seemed to disappear into the realms of magic and was left as something scientists have never been able to explain," he says.

Eventually he gained access to a wind tunnel in Wellington and, through a variety of tests which proved more accurate than any published before, he was able to eliminate humidity as a factor in swing, something that has not yet been taken on board by cricket commentators the world over.

Wilkins cites occasions of high humidity in Brisbane when the ball has not swung at all, and other occasions of dry heat in Karachi or Adelaide when the ball has swung, as evidence of his findings. The swing, he says, occurs because of the lack of turbulence in the air caused by the sun heating the ground.

Not content with having solved the mysteries of one aspect of the game, Wilkins is now working on a mechanism to test the speed of pitches by measuring the grip of the ball on the wicket. He hopes it will be useful in pitch preparation. If past form is any guide, his findings might be appreciated more overseas than in New Zealand.