Lotto’s top prize to hit $60m – but it’s never been harder to win

From September 13 Lotto’s Powerball is changing, with predictions of thousands more weekly winners. We asked a mathematician to calculate the chance of striking the big one.

With a top possible jackpot of $60 million, Powerball is poised to get its biggest shake-up in nearly two decades.

The changes take effect from mid-September so Saturday’s Lotto draw is not affected.

But from next month Lotto will increase the number of Powerballs from 10 to 14 and will raise the minimum and maximum jackpots and introduce a new prize division.

Lotto says the changes will mean “bigger prizes, bigger jackpots and more chances to win”.

But there’s a catch: winning the big prize will become significantly harder.

How much harder will Powerball be to win?

The number of Powerball numbers to choose from will increase from 10 to 14.

That might not sound like much. But it means the odds of winning Powerball Division 1 will jump from one in 38.4 million to one in 53.7 million.

Auckland University mathematician Melissa Tacy says adding four more Powerball numbers has a much bigger impact than people might expect.

“The way that we count out the number of different draws is multiplicative,” she said.

“So even though it’s only four more, you’re multiplying that by an awfully large number already. When you take a really large number and even multiply it by something small, you get a really, really big change.”

Just how unlikely is one in 53.7 million?

Tacy puts it this way: under the current system, the odds are roughly equivalent to finding one person among seven copies of New Zealand’s population. After the changes, it will be more like trying to find one person among 10 copies of the country.

Bigger jackpots and a new prize division

While the odds of winning the big prize are getting even longer, the potential jackpots are getting bigger.

The starting jackpot will increase from $4 million to $5 million, while the maximum jackpot will rise from $50 million to $60 million.

At around the same time, Lotto says a new Division 8 prize pool will mean there are more winners overall.

The existing Powerball divisions, meanwhile, will become harder to win. Lotto forecasts there will be about 9000 fewer winners across Divisions 1 to 7 each week.

But the introduction of Division 8 means Lotto expects the total number of winners to increase.

The catch? Those winners will receive a fixed prize of $12 – regardless of the total prize pool up for grabs.

Tacy says the new division is easier to win because players need to match fewer numbers.

“They’re more likely to win smaller prizes more often,” Tacy said.

Why make it harder to win big?

Lotto says the changes are designed to keep Powerball “fresh and exciting” while continuing to support community causes.

But there is another reason the odds matter: the harder the jackpot is to win, the more likely it is to roll over.

“Because each time you are less likely to win, the prize is more likely to roll over every week,” Tacy said.

And as jackpots grow, so do ticket sales.

Lotto says a $20 million jackpot can generate around 60 per cent more ticket sales than a $4 million draw.

Is there any way to pick better numbers?

Sorry, but no.

Despite the elaborate systems, lucky numbers and carefully studied patterns used by some players, Tacy says every number combination has exactly the same probability of being drawn.

“There is no way of picking your Lotto numbers that gives you a better chance,” she said.

Lotto did reveal that, over the past five years, 17 and 24 have been the most frequently drawn Lotto numbers, while Powerball number 1 has appeared most often.

Tempting as that might be, it does not mean those numbers are more likely to come up next time.

Tacy says humans are naturally drawn to patterns, but random events can produce apparent patterns that have no predictive power.

“With random events, all patterns are equally likely,” she said.

Knowing the odds doesn’t necessarily stop people from playing. As Tacy puts it, sometimes the fun is simply imagining: What if?

“I have enjoyed buying a Lotto ticket and doing all of the imagining about, ‘What if?’ It’s fun,” she said.

From mid-September, those dreams will come with longer odds but bigger potential jackpots. Lotto says ticket prices will stay the same.

The final draw under the current 10-Powerball format will be a Must Be Won draw on Saturday 12 September. The jackpot amount will be confirmed prior to the draw.

This means if there are no winners in Powerball Division 1, the jackpot will be shared in the next division down where there are winners.

Tickets for the refreshed game will go on sale from Sunday September 13, ahead of the first draw under the new format on Wednesday September 16.

Watch on TVNZ+: The biggest change to Lotto in decades