One man wears green underpants when he plays poker machines and woman has banned her husband from watching her play as he gives her "bad luck".

A new study to be presented at a hospitality management summit in Sydney next week reveals 40% of gamblers believe superstitions can lead to big wins on poker machines.

Colin Farrell, a student in the University of New South Wales' hospitality marketing course, said his study showed a majority of gamblers believed "good luck" could help them win and few believed it was just a game of chance.

Mr Farrell investigated why the generally accepted belief that "the more you gamble, the more you lose" did not dampen the industry's appeal.

He found 60 per cent of his study of 60 gamblers at a Sydney club believed they could win "when their luck changed."

Many believed in "down cycles", Mr Farrel found.

One gambler spoke of having a "lucky week" each month.

"He said it was just a matter of working out which week it was," Mr Farrell said.

"Gamblers are in a vicious circle. They think if they do win, it's a lucky sequence and if they don't win, they're about to enter a lucky sequence."

A majority of gamblers also believed machines ran in sequences, with 57 per cent stating they would stick with a machine because it was "ready to pay out".

Ninety per cent of the sample ranked a sequence of heads and tails to show a likely win. Women tended to prefer a constantly changing run, whereas men chose long sequences.

Forty per cent of gamblers believe superstitious behavior bring them luck.

One woman refuses to cross her legs when gambling and winks at a machine, while a third woman puts an orange next to the machine and pats it gently.