Stirling Hamman came up with the idea in the back of a taxi. On a cricket tour in Trinidad, the Australian, heavily involved in veterans cricket in New South Wales, wondered whether there might be an appetite for an Over-50s World Cup. It had never been done before but Hamman knew that veterans cricket was a growing force within the amateur game in a number of countries. The interest was almost certainly there, he thought, but could he make it a reality?

Now, eighteen months later, eight squads from Australia, England, New Zealand, South Africa, Canada, Pakistan, Sri Lanka and Wales have assembled in Sydney ready for a 34-game tournament that takes place over three weeks at a number of New South Wales club ovals. It has taken a lot of work to set things up, most of it by Hamman himself, but on the eve of the tournament, the Australian's hope is that the cricket showcases the enjoyment, fairness and respect which he says are key themes of veterans cricket.

This will not be the first international cricket to be played at over-50 level. There have been various informal tours and series - although there is some debate as to when the first official veterans international match took place - but this will be the first World Cup. Although it is not an official ICC tournament, the competition has been given approval by Cricket Australia and Belinda Clarke, former Australian international, will attend the opening ceremony on their behalf. Another former Test cricketer, Trevor Chappell, the tournament's ambassador, will also be there.

Cricketers playing past their fiftieth birthday at club level is not unusual but organised over-50s cricket is still a relatively new concept. The eight countries competing in Australia have varying domestic structures, ranging from the relatively well developed to the non-existent. In England, Pakistan and Australia, there are well-established over-50 competitions but in New Zealand for example, there is no over-50 tournament yet. Their squad has been selected from those eligible players still playing club cricket.

The make-up of the squads is equally varied. Ijaz Ahmed, a veteran of 60 Tests and 250 ODIs, is captaining Pakistan and is joined by another three former Pakistani internationals in their squad, while New Zealand have included fast bowler Richard Petrie, who played 12 ODIs. The vast majority of the players on show, however, will be good quality club cricketers. "Most of the former international or first-class players are either not interested in playing the game anymore, are not fit enough, could not take three weeks off work or simply could not afford it," says South Africa's team manager Roger Moult.

"We had some former international players who were interested, but when they realised that the make-up of the team was going to be more club-based, they withdrew. Out of the 16 players, at least 13 of them have represented their province at some stage of their lives. Most of them have played Premier league club cricket."

For most of those playing over the next three weeks, representing their country at cricket will have been little more than a pipe dream. Now, at the back-end of their playing careers, the unthinkable is happening. "It's a big honour," Jim Morrison, New Zealand's team manager, says. "The highest level most would have got to is either first-class cricket or more likely some local representative teams. Playing for your country at whatever age-group it is, is a big honour. Everyone is really proud and determined to do their best for their country.

"A lot of the guys were planning to give cricket away or almost had because there was no real reason to keep going. For them, it's been a real shot in the arm. They can get fit again, and they are really motivated to play some serious cricket rather than playing golden oldies cricket against guys who just want to have a beer and a bat and go home. For the guys in their forties, it's a reason for them to keep going. They've come out and said they'd love to be involved when they pass fifty."

For many others, the tournament will be the highlight of a lifetime involved in the game. "As 50 year-olds, we all thought international honours were a distant ambition," Paul Donovan, tour organiser for the Wales squad, wrote in their official World Cup brochure. "Many of our squad are senior officials at the clubs they represent and they are all worthy members of the squad for the dedication they have put into grassroots cricket. It's great reward for a lot of hard work."

Much over-50 cricket around the world is organised informally through volunteer organisations, so it does not yet fall under the auspices of the respective governing bodies. As a result, the World Cup squads have had to fund their own trips. Which is not to say the governing bodies are not supportive. New Zealand Cricket, for instance, may have not given any financial assistance to the 'Greycaps' squad but they have helped in a number of other ways.

Alongside some promotional support - the squad announcement was posted on the New Zealand Cricket website - they have made a stash of old Black Caps kit available, have given the squad access to their hire car discount and provided their corporate excess baggage allowance so the cost of shipping cricket kit to Australia has been reduced. Sponsorship has also made a huge difference to many of the teams but there has still been a considerable financial burden for the players who have had to take time off work in the process.

Moult reckons it will cost each South African player about USD $4,200 but they are just happy to be in Australia after their participation looked in doubt at one stage. Cricket South Africa has refused to endorse the team because the squad does not meet the transformation targets which their international sides must adhere to. According to Moult, that has not been for the want of trying and although several players of colour are included, others who were asked to participate could not because of finance or work reasons. CSA have not, however, blocked Moult and his men's participation.

Predicting the competition is tricky given the different domestic structures in place and the unknown strength of each side, but one thing is certain: fitness will be key. Australian captain Peter Solway's preparation for the tournament has, he joked, involved little more than walking his dogs so as to not risk injury. New Zealand and Sri Lanka - skippered by Marlon Von Hagt who played first-class cricket in both Sri Lanka and New Zealand - have placed a premium on getting fit, recognising that injuries may play a big part in such a packed tournament, with teams playing seven group games in just under two weeks.

The top four teams will then go through to the semi-finals and finals while the remaining sides will contest a plate round. Although there are various social functions planned for the duration of the tournament, including the obligatory golf day, the cricket will be serious and hard-fought. "We are not a social team," says Moult. "We are participating with the intention of ending in the top four. We do, however, intend to showcase the very best of South Africa. We also intend highlighting the plight of the rhino which is a very important part of our mission in Australia."

While much of the media coverage of cricket is focused, understandably, on the men's and women's professional game, the over-50s World Cup is a reminder that amateur players are the heartbeat of the sport, playing it for the simple pleasure of the game itself, the physical and mental benefits and the camaraderie. For those players contesting a World Cup over the next three weeks in Australia, it will be a once in a lifetime experience, something most of them never thought possible. Winning will be important, but it won't be everything. Just as cricket - indeed all sport - should be.