Has the Same Lottery Combination Ever Been Drawn Twice?
In September 2009, the Bulgarian lottery drew 4, 15, 23, 24, 35 and 42. Four days later, it drew 4, 15, 23, 24, 35 and 42 again! It made headlines around the world, 18 players won the Jackpot the second time, and an investigation was ordered. Which found... nothing. It was just chance.
So how unlikely is it for the same winning numbers to come up twice? We compared every draw in our data with every other draw, 4,108,659 pairs in all, to find out. Let's see what turned up!
- Have any numbers repeated?
- It happened here too!
- Why it's less unlikely than you'd think
- The near misses
- Should you play numbers that have already won?
Have any numbers repeated?
We checked each lottery in its current format, comparing only the main numbers. Saturday Lotto and Weekday Windfall draw 6 numbers from the same 45, so we checked them together, and the same goes for the 5 main numbers of EuroMillions and Eurojackpot.
| Lottery | Draws | Possible combinations | Chance of a repeat | Repeats found |
|---|---|---|---|---|
| Saturday Lotto and Weekday Windfall | 1,667 | 8,145,060 | 15.7% | 1 |
| EuroMillions and Eurojackpot | 1,507 | 2,118,760 | 41.5% | 0 |
| US Powerball | 1,427 | 11,238,513 | 8.7% | 0 |
| Mega Millions | 940 | 12,103,014 | 3.6% | 0 |
| Australian Powerball | 446 | 6,724,520 | 1.5% | 0 |
| Oz Lotto | 234 | 62,891,499 | under 0.1% | 0 |
It happened here too!
In Saturday Lotto and Weekday Windfall, the winning numbers 10, 11, 16, 17, 20, 24 have been drawn twice:
| Draw | Winning numbers | Supplementary numbers | Division 1 winners |
|---|---|---|---|
| Monday 29 June 2020 | 10, 11, 16, 17, 20, 24 | 15, 34 | 1, $1,000,000 each |
| Wednesday 7 April 2021 | 10, 11, 16, 17, 20, 24 | 5, 8 | 5, $800,000 each |
That's 282 days apart, in what was then Monday and Wednesday Lotto, today's Weekday Windfall. Only the supplementary numbers were different.
And look at the winners: 1 the first time, but 5 the second. It looks like some players kept playing the numbers that had already won!
Why it's less unlikely than you'd think
The chance of a particular draw repeating the numbers of another particular draw is tiny: 1 in 8,145,060 in Saturday Lotto. But that's not the question! With 1,667 draws, there are 1,388,611 pairs of draws that could match, and each pair is another chance. All up, there was a 16% chance of at least one repeat.
It's the same reason why, in a room of just 23 people, there's a 50% chance that two of them share a birthday. You're not asking whether someone shares your birthday, but whether anyone shares a birthday with anyone else, and that's a lot of pairs.
In fact, the most likely repeat on our list didn't happen: with 1,507 draws of 5 numbers from 50 between them, EuroMillions and Eurojackpot had a 41% chance of at least one repeat, and there hasn't been one. Yet.
The near misses
Exact repeats are rare, but draws sharing most of their numbers are not. Here's how many pairs of draws had 4 or more numbers in common, against what pure chance predicts.
| Lottery | Numbers in common | Pairs of draws | Expected by chance |
|---|---|---|---|
| Saturday Lotto and Weekday Windfall | 6 of 6 | 1 | 0.2 |
| Saturday Lotto and Weekday Windfall | 5 of 6 | 47 | 40 |
| Saturday Lotto and Weekday Windfall | 4 of 6 | 1,855 | 1,895 |
| EuroMillions and Eurojackpot | 5 of 5 | 0 | 0.5 |
| EuroMillions and Eurojackpot | 4 of 5 | 126 | 121 |
| US Powerball | 5 of 5 | 0 | 0.1 |
| US Powerball | 4 of 5 | 26 | 29 |
| Mega Millions | 5 of 5 | 0 | 0.0 |
| Mega Millions | 4 of 5 | 10 | 12 |
| Australian Powerball | 7 of 7 | 0 | 0.0 |
| Australian Powerball | 6 of 7 | 4 | 2.9 |
| Australian Powerball | 5 of 7 | 125 | 117 |
| Australian Powerball | 4 of 7 | 1,757 | 1,692 |
| Oz Lotto | 7 of 7 | 0 | 0.0 |
| Oz Lotto | 6 of 7 | 0 | 0.1 |
| Oz Lotto | 5 of 7 | 4 | 7.1 |
| Oz Lotto | 4 of 7 | 152 | 150 |
The real draws and pure chance are remarkably close, every time. No hidden patterns, no favourite combinations: just random balls doing what random balls do.
Should you play numbers that have already won?
They're just as likely to come up as any other numbers, no more, no less. But you might have company: as the second draw above shows, plenty of players do the same. If they come up again, you'll be sharing the prize.
We put that and 6 other strategies to the test in we tested 7 lottery strategies, and you can see which numbers have come up the most on our most common numbers pages, like the most common Saturday Lotto numbers. Or try your own numbers for free in our lottery simulators!