What Is a Must Be Won Draw?

Updated 16 September 2026. New Zealand's Powerball rules changed on 13 September 2026: the Powerball pool grew from 10 balls to 14, Division 1 odds are now about 1 in 53.7 million per line, a new Division 8 was added, the starting jackpot rose to $5 million and the cap lifted from $50 million to $60 million. Where this article quotes odds, ball counts or jackpot limits, they describe the game as it was before that date. The current numbers are on Powerball is changing on 13 September 2026.

Most weeks the Powerball jackpot does one of two things: someone wins it, or it rolls over and grows. A Must Be Won draw is the third case — the night the jackpot has run out of room and the money has to leave the building.

Saturday 12 September is one of those nights, and it's an odd one even by Must Be Won standards. Here's what the rule actually does, and what the last nineteen years of data say about how these draws tend to end.

The rule, plainly

Under the current game rules the Powerball jackpot can't roll past $60 million, and it can't run for more than 52 consecutive weeks. Hit either limit and the next draw is Must Be Won.

The mechanism is a roll-down. If nobody matches Division 1 that night, the entire jackpot moves to the next Powerball division that has winners — normally Division 2 — and is split equally if there's more than one winner there.

So the guarantee isn't "someone will hit the jackpot". It's "the jackpot will be paid out". Those are different things, and the difference matters a lot more than most people expect.

Every Must Be Won draw so far

Thirteen draws, and the single thing that stands out is how rarely one person takes the lot.

The pattern worth noticing

Seven of the twelve completed Must Be Won draws were shared. Only five produced a sole winner.

That's not a coincidence, and it's not luck evening out. Big jackpots pull in people who don't normally play — Lotto NZ's own communications team has said as much, describing customers who only show up once a jackpot passes $20 million or $30 million. Sale volumes roughly quadruple between a $4.5 million and a $40 million jackpot.

More tickets means more chances that two people picked the same six numbers, and it means the lower divisions are crowded too — which is exactly why the roll-down so often lands on a group rather than an individual.

The two extremes make the point neatly. In 2016 an Auckland couple took the whole $44 million alone. Six years earlier, ten strangers split $50 million into $5.02 million slices.

Why 12 September is different

Every previous Must Be Won draw happened because the jackpot hit a limit. This one is happening because the game is changing.

From Sunday 13 September the Powerball pool grows from 10 balls to 14, Division 1 odds lengthen from 1 in 38.4 million to 1 in 53.7 million, the starting jackpot rises from $4 million to $5 million and the cap goes from $50 million to $60 million. Saturday 12 September is the last draw under the old rules, so whatever is sitting in the jackpot has to be paid out before the new game starts fresh.

In other words: this is a housekeeping Must Be Won, not a record-chasing one. The prize will be whatever the last few draws build it to, not $50 million.

After that, the first draw under the new format is Wednesday 16 September, starting at $5 million. Tickets for the new game can't be bought until 13 September, so the last advance-purchase draw is 12 September.

What doesn't change

The odds per line are 1 in 53,737,320 whether the draw is Must Be Won or not (1 in 38,383,800 before the 14-ball change), and every draw is independent of the last. A roll-down doesn't make anyone more likely to win Division 1 — it only changes where the money goes if nobody does.

If you're playing on Saturday, it's worth knowing that the most common outcome of these draws isn't one person getting rich. It's several people getting a phone call they weren't expecting.