Lottery addicts could avoid sharing their jackpot prizes with other winners by choosing more than one number over 40 and picking numbers that are adjacent to each other, a mathematician from Sussex University has said.
Such combinations turn up frequently yet people pick them far less frequently than expected, according to John Haigh, reader in statistics.
National Lottery players pick six numbers between one and 49, in any order. They win a prize if at least three of their numbers match the numbers on six balls drawn at random on a Saturday night. The chance of picking all the same numbers (the jackpot) is about one in 14 million. If 65 million tickets are sold then, each week, there should be about five winners.
So Dr Haigh was baffled last January, in week nine, when there were 133 winners of the jackpot. "133 is utterly, utterly outrageous," he said. "This meant that there was something about that particular set of numbers that was attractive to a lot of people." The winning combination was: 7, 17, 23, 32, 38, 42.
Dr Haigh has found other mystifying lottery results. If people picked their numbers truly randomly, the frequency with which no one picks the winning six should be about once every two years. Yet the lottery has run for less than a year (48 weeks) and there have been nine non-winning weeks.
"This is all overwhelming evidence of the non-randomness of choice," said Dr Haigh, who has analysed the first 30 weeks of lottery winners in the bulletin of The Institute of Mathematics and its Applications. "People are pretty bad at being random: they select numbers too evenly spread." Players are less likely to choose two adjacent numbers, despite the counter-intuitive fact that half of the winning combinations will contain them.
But if you want to make use of this information, do it quickly. As soon as the news gets around, gambling patterns may change, said Dr Haigh.