'Fun' is a word the quietly spoken Hong Kong-based players use whenever mahjong is mentioned.

All three say they only got serious about winning the competition when they knew they had secured 32nd place last year - a position which guarantees a minimum of US$5,000.

The competition offers the winner prize money of US$500,000 and a championship trophy worth HK$150,000. The second runner-up wins US$150,000, the third runner-up gets US$80,000, while fourth runner-up can walk away with US$50,000.

The tournament attracted more than 300 contestants from 15 countries last year. The event went on for three days and there were 12 hours of four elimination rounds.

None of the Hong Kong players wants to disclose what made their game special - a dictum that explains the principle of playing mahjong. In a game of mahjong you want to observe your opponents' games and read their minds, while never letting them know yours. The better you are at spotting their strategies, the less likely you will lose.

They play, on average, two or three times a week and, in Mr Ho's case, once a month. 'I don't play regularly. I didn't even play for six months before the tournament,' says Mr Ho, a financial adviser and team manager at AIA, part of the AIG group.

But to compete or even to win in a major tournament surely requires a lot of practice? 'No. But you need a lot of luck,' says Mr Hui, who is a retired designer. 'If the lucky streak is with you, you get a good set of tiles to play with and you win the round. If you get to the finals, then you can start thinking about tactics or using your experience.'

During competition, the tables can turn very quickly, the players say. If you are down or on the verge of losing, there's nothing to lose by taking risks to get a higher scoring sequence.

Mr Ho won last year's tournament by coming from behind, playing more aggressively against the top scorer, Shigeru Aono of Japan, who lost many points later in the game and eventually finished fourth after leading the first few rounds.

'All along before getting to the final, my thinking had been that if I had a good set of tiles to start with I'd try to play my best to get a good score. If I didn't get a nice set of tiles to play with, I'd be more defensive, taking the safer options, making sure I had enough points to qualify for the next round,' Mr Ho says.

'I didn't think about winning the championship when I got through to the final,' Mr Ho says. 'I'd achieved my goal by getting this far. I knew I could take home at least US$50,000 even if I lost.'

Mr Ho says he is never under any pressure to win and because of this he plays more freely. His willingness to take risks for a higher scoring sequence eventually led him to win the last two hands of the final round in last year's world event.

The thrill of playing mahjong and, to a certain extent, taking part in the tournament, according to the players, is that, unlike card games, you have some degree of control.

'There are certainly more variations with mahjong,' Mr Tse says. 'With Cantonese mahjong, you can observe what the other three players are doing and control your own game. There are 13 tiles for each player, and you don't have to give away anything and the game still goes on.'

While acknowledging that winning the tournament was the highlight, the players say that they rarely use it as a means of profit and are selective about whom they play with.

But how do they rate their luck? 'I think I am quite lucky, I rarely lose a lot at a mahjong table,' Mr Hui says.

They differentiated themselves from professional gamblers, putting a few hundred dollars at most every now and then on the table. Certainly, none of them will ever bet more than they can afford. 'The worst type of players you can meet at a mahjong table are those who lose their temper if they are losing money,' Mr Ho says.

All three players have an even temper and believe that mahjong is not a game for someone who cannot handle losing.

Asked if there are any other games that they dabble in occasionally, it is clear that mahjong comes up as the top choice, although Mr Tse says he is also interested in horse racing.

But giving up the day job and turning professional is not an option for the three players. 'I think if you have very good technique and use your experience you can play every day at mahjong venues to make a living,' Mr Tse says. 'But I don't think it's practical or realistic.'

Many people get into mahjong because they like to gamble, say the players. 'To be a professional gambler, I'd think you'd need to have a strong mentality,' Mr Tse says.

Apart from Mr Ho, who has a free pass to enter the competition in September this year because he is the reigning champion, Mr Hui and Mr Tse say that they have not decided if they will participate in the tournament at the Wynn Macau. To take part competitors have to pay US$1,000 upfront.

The lack of tournaments in Hong Kong means that there are fewer opportunities to train players who want to compete in the world event. Japan, for example, has a national association which educates people about mahjong and organises tournaments and regional competitions.

'The standard of playing is very high among the Japanese players,' Mr Ho says. 'Players are ranked and there are competitions every month. You can really tell these players are technically competent.'

For now, the players are happy to get together for a few rounds of mahjong just for fun.