A statistician says there's not much Lotto players can do to increase their chances of winning New Zealand's largest ever jackpot tomorrow night.

However, they can minimise their chances of having to share the prize.

The largest jackpot ever on offer, of $40 million, must be won tomorrow.

Professor Thomas Lumley, of the University of Auckland, said Lotto draws were completely random so players could do no better than picking a random set of numbers.


"How you pick the numbers won't change your chance of winning. It will only change how many people you share the prize with."

If players picked the same numbers as a lot of others, they would end up sharing the prize if they did win.

It was hard to know what numbers others were selecting. But picking a simple sequence or a set of low numbers that correlated with dates could be a bad idea.

"It's hard to predict what sort of patterns people will choose, which is why getting a computer pick is a good thing to do."

Lumley said it didn't matter whether somebody picked the same or different numbers each time they played Lotto.

"You can watch the draw on television and you can see that, you know, it's just jumbling balls around. It doesn't have any memory."

It seems unlikely Lumley will be buying a ticket for tomorrow's draw.

He said most people who played the Lotto didn't think they were going to win but liked to think about what they would do if they did win. Statistician were just as capable of that as anyone else. "It's just when you've done enough generating random numbers for work, generating random numbers for fun gets less interesting."

Chief Executive of Lotto NZ, Wayne Pickup, said queues were forming in Lotto stores around the country this morning, with four times as many tickets being sold every hour than at the same time last week.

Lotto had to deliver more ticket paper to all its stores to make sure they didn't run out, he said.

In a Must Be Won draw, if there were no first division winners, the entire jackpot rolled down to the next division where there were winners - for example, second or third division.

If there was more than one winner in that division, the total jackpot was shared evenly among all winners.