Higher the numbers, bigger the prize: expert

Many people take birthday numbers. Photo / Dean Purcell

New advice has been issued for Lotto punters wanting to hook a big prize - choose high numbers.

Kiwis buy about a million tickets each week but this latest tip will have come too late for those chasing last night's $15 million Powerball.

The odds of winning - an outlay of $6 buys a one in a 383,838 chance of hitting the Lotto jackpot - won't change whichever numbers you pick, but you will lessen your chances of having to share the top prize.

Two weeks ago, a $2 million prize was divided by three tickets - meaning each went home with just under $670,000. Most people would be comfortable with that sort of return, but if splitting your millions doesn't tickle your fancy, AUT University's probability expert, Dr Robin Hankin, has a tip: Don't pick your own numbers.

"People aren't very good at choosing random numbers. We go for our date of birth or children's age or lucky number seven and, the problem is, a lot of others will pick those numbers too." If you must pick your own, he suggests avoiding numbers below 31, or at least 12, to get away from "date" numbers.

Hankin added consecutive numbers were good too, because other people tended not to "like the look of them".

Just don't lazily pick one, two, three, four, five and six - it's somewhat of an exception with 1725 individual tickets for the draw two weeks ago carrying this sequence. If those numbers came in, a standard $1 million prize would dwindle to just $571.71 per person.

But there was one curve ball his probability formulas couldn't account for: Despite everything, numbers one and seven were the most common numbers to fall out of the wheel in New Zealand.

"That's what we would call statistically significant ... because that would be very special," he said.