Imagine checking your lottery ticket and discovering that you've won £16 million. You read the numbers again, perhaps call someone to check them for you, and begin doing the kind of mental arithmetic that has very little to do with mathematics. The house you could buy. The job you could leave. The people you'd tell first.
Now imagine finding out that 132 other people are having exactly the same moment.
On 14 January 1995, the UK National Lottery produced one of the strangest results in its history. A total of 133 tickets matched all six winning numbers, splitting a jackpot of approximately £16.3 million into individual prizes of £122,510 [1]. Still an extraordinary amount of money, of course, although rather less than the fortune each winner might have imagined a few moments earlier.
The numbers were 7, 17, 23, 32, 38 and 42. Written down, they don't look especially remarkable. On the printed lottery slip, however, they occupied a distinctive arrangement across the central columns, creating a pattern that may have appealed to people filling in their tickets [1].
We can't know why each winner selected that combination. Some might have noticed the pattern, while others could have arrived at the same numbers for entirely different reasons. But the result exposed something peculiar about a game built around chance: the numbers drawn by the machine were random, while the numbers people chose were anything but evenly distributed.
And the more closely researchers have examined those choices, the stranger they've become.
Why Seven Feels Random
The original UK National Lottery required players to choose six numbers from 49, creating 13,983,816 possible combinations. Every one had exactly the same chance of being drawn, whether it consisted of consecutive numbers, birthdays or an apparently meaningless assortment.
Choosing them, though, was another matter.
Some people have used the same sequence for years. Others rely on anniversaries, family birthdays or numbers that have acquired some private significance. Even those who avoid meaningful dates often look for a combination that feels convincingly random, as though certain numbers were better at representing chance than others.
Psychologists Michael Kubovy and Joseph Psotka explored a related tendency in 1976. They approached 558 people on the Yale campus and asked them to report the first digit that came to mind. Seven accounted for 28.4% of the responses [2].
The result is familiar enough to seem almost inevitable. Seven has a long cultural association with luck, and it possesses a few qualities that make it an appealing choice. It's odd, prime and less immediately neat than five or ten.
But the researchers weren't simply interested in establishing that people liked seven. They wanted to understand why it appeared so frequently when participants were supposed to respond spontaneously.
When the instructions changed, so did the answers. Asked for a number between six and fifteen, participants became less likely to choose seven. Its popularity also dropped when the experimenter mentioned it as an example.
The findings suggested that people were selecting numbers partly according to what they believed would count as a spontaneous response. Rather than producing an entirely unplanned answer, they seemed sensitive to the expectations created by the question itself.
There's a certain irony in trying to choose a random number. Five can feel too ordinary, ten too predictable. Seven, with its slightly awkward mathematical personality, seems more convincing. The thought may feel spontaneous precisely because the answer looks as though it hasn't been carefully chosen.
Of course, the experiment doesn't establish why every individual favours seven, and preferences can vary across populations and contexts. What it does show is how easily a seemingly instinctive decision can be influenced by a shared understanding of what an appropriate answer should look like.
Lottery players have another source of shared preferences, one that feels considerably more personal.
Birthdays.
Someone choosing their daughter's birthday and someone choosing a wedding anniversary may have entirely different memories attached to those dates. Yet both are selecting from the same calendar, which means their choices are largely concentrated between 1 and 31. In a lottery offering numbers up to 49, that leaves a substantial part of the available range outside the dates most people would naturally consider.
Research into actual lottery selections has found preferences for lower numbers, familiar dates and particular combinations [3]. Across millions of tickets, choices rooted in individual memories begin to form recognisable patterns.
But personal associations are only part of the explanation. Sometimes, what matters is simply where a number appears.
The Influence of a Piece of Paper
Think about choosing a seat on a plane or selecting a date from an online calendar. You probably don't examine every available option with equal attention. Your eyes move across the arrangement, certain positions catch your attention and some choices feel more convenient or appealing than others.
A lottery slip presents numbers in much the same way, although its layout might seem too ordinary to influence anything.
In 2021, researchers Brian Polin, Eyal Ben Isaac and Itzhak Aharon examined more than 800 million manually selected number entries from 118 consecutive Israeli lottery draws [4]. The dataset allowed them to observe preferences on a scale far beyond what could be captured in a conventional laboratory experiment.
Some findings were unsurprising. Particular numbers remained consistently popular, including seven. More revealing was the influence of the selection form itself.
Numbers appearing in the first horizontal row were chosen more frequently than those in the fourth row. The researchers considered whether players might be scanning the form from top to bottom, selecting numbers as they went and leaving fewer choices available by the time they reached the lower rows.
That explanation couldn't be established for every player, but the association between position and selection was clear. Other lottery research has also identified preferences for numbers near the centre of the ticket [3].
A player doesn't need to think consciously about the layout for it to matter. Perhaps a pattern catches their eye, or a group of numbers looks more pleasing than another. What feels like a preference for the numbers themselves may partly reflect how those numbers have been arranged.
The 1995 jackpot is a striking example of the possibilities. Its winning combination formed a distinctive pattern on the playslip, and that visual arrangement offers a plausible explanation for why so many tickets carried identical numbers.
Nobody needed to coordinate. They were all looking at the same form.
There is a broader point here about the environments in which decisions happen. A grid, a menu or a booking screen may appear to be a neutral collection of options, but the way those options are presented can affect what people notice and ultimately choose.
Usually, the consequences are difficult to isolate. In a lottery, where multiple winners may have to share the same prize, they can be measured in money.
The Price of Choosing Seven
In 2025, researchers Patrick and Tristan Roger investigated whether the popularity of particular numbers affected lottery payouts. Their study examined data from Belgium, France and EuroMillions, focusing on the financial consequences of choosing seven [5].
The results were surprisingly substantial.
In one Belgian Lotto example, tickets containing seven received an average third-rank prize of approximately €1,183, compared with €1,610 for tickets without it. That represents a difference of 26.5%.
The study found that the disadvantage associated with selecting seven was more typically between 10% and 20% across the games examined.
Seven hadn't become less likely to appear in the draw. The difference arose because certain lotteries distribute a prize pool among qualifying winners, so a popular selection can mean sharing that pool with more people.
Consider two combinations with identical chances of being drawn. One is selected by thousands of players, while the other appears on relatively few tickets. If either combination wins in a shared-prize game, the number of people holding matching tickets can make a considerable difference to the payout.
This affects what economists call expected value, the average financial return calculated by accounting for the likelihood and size of possible payouts.
It creates a distinction that isn't immediately obvious when filling in a lottery slip. Although every valid combination has the same chance of matching a fair draw, its expected financial return can depend on how many other people have selected it.
The researchers also accounted for the preference for birthday-related numbers, finding that the financial disadvantage associated with seven persisted beyond that tendency [5].
The finding gives an unexpectedly practical consequence to something that began as a psychological curiosity. A number's reputation for being lucky can make it popular enough to reduce the prizes received by some of the people who choose it.
Naturally, this raises the possibility of doing the opposite.
Would Unpopular Numbers Be Better?
In 1998, mathematicians Simon Cox, Geoffrey Daniell and Denis Nicole investigated whether lottery players could improve their expected winnings by avoiding popular combinations [6].
Using data from the early UK National Lottery, they developed a model to estimate how frequently players selected particular numbers and combinations. Their analysis found preferences for numbers towards the centre of the ticket and suggested that choosing unpopular combinations could approximately double expected winnings under the conditions they studied.
The word double is doing quite a lot of work there.
The researchers weren't suggesting that an unpopular combination was more likely to appear in the draw. The potential advantage came from the possibility of sharing a prize with fewer winners. And because the expected return on a lottery ticket can remain below its purchase price, doubling that return doesn't necessarily make playing profitable.
There are also limits to how widely the finding applies. Some games offer fixed payouts, meaning that the popularity of a combination doesn't reduce the amount awarded to each qualifying winner. In shared-prize lotteries, preferences can change between countries, games and periods, while detailed information about players' selections isn't always publicly available [7].
A randomly generated ticket avoids deliberately following birthdays or familiar patterns, but it can still produce a popular combination by chance. There is no guarantee of being the only person holding a particular set of numbers.
The research therefore offers no reliable way to predict a winning draw or turn lottery play into a sound financial decision.
For the 133 winners in January 1995, none of those considerations would have changed the numbers already printed on their tickets. By the time the draw took place, the decisions that determined how widely the jackpot would be shared had all been made.
The Numbers We Share
The most unusual part of that January draw wasn't the winning combination itself. It was the number of people who had chosen it, each with access to the same grid of numbers but without knowing what anyone else had selected.
There's something familiar about that experience outside the lottery. We develop tastes, routines and small personal rituals without spending much time considering how many strangers might share them. The reasons behind our decisions are available to us in a way that other people's reasons aren't, which can make our choices feel more distinctive than they turn out to be.
One hundred and thirty-three winning tickets, all carrying the same six numbers, held by people who had no need to know what anyone else was choosing.
They hadn't copied one another.
They had simply found the same numbers worth choosing.
References
[1] National-Lottery.com. What Are the Most Unusual Lotto Results Ever?.
[2] Kubovy, M., & Psotka, J. (1976). The Predominance of Seven and the Apparent Spontaneity of Numerical Choices. Journal of Experimental Psychology: Human Perception and Performance, 2(2), 291–294.
[3] Wang, T. V., Potter van Loon, R. J. D., van den Assem, M. J., & van Dolder, D. (2016). Number Preferences in Lotteries. Judgment and Decision Making, 11(3), 243–259.
[4] Polin, B. A., Ben Isaac, E., & Aharon, I. (2021). Patterns in Manually Selected Numbers in the Israeli Lottery. Judgment and Decision Making, 16(4), 1039–1059.
[5] Roger, P., & Roger, T. (2025). Costly Number Seven. Economics Letters, 255, 112519.
[6] Cox, S. J., Daniell, G. J., & Nicole, D. A. (1998). Using Maximum Entropy to Double One's Expected Winnings in the UK National Lottery. Journal of the Royal Statistical Society: Series D (The Statistician), 47(4), 629–641.
[7] Hanley, J., & Cronin, M. (2023). Which Lottery Numbers Do Players Play?. Significance, 20(1), 31–33.