Statistician Reveals Flaws In Scratch Lotteries

Wired offers a fascinating report of how a statistics expert was able to crack the “codes” of several scratch lottery games. A few years ago, Mohan Srivastava of Toronto studied a tic-tac-toe game that won him a small cash prize and found that the visible numbers, in how there were placed on the board, were able to reveal the hidden numbers without needing to scratch the latex coating on the game. Suspecting that he may be onto something, Srivastava started to analyze several other kinds of lotteries such as Super Bingo and sure enough, was able to crack their codes too with a good accuracy.

Instead of using his new found knowledge in exploiting the lotteries, he contacted several lottery organizations in Canada and the US, some of which acknowledged the flaw in their games. He also suspects that criminal groups too may find holes in such games and use it to plunder the lotteries, though there is no solid evidence that anyone has done so.

Wired reports:

As a trained statistician with degrees from MIT and Stanford University, Srivastava was intrigued by the technical problem posed by the lottery ticket. In fact, it reminded him a lot of his day job, which involves consulting for mining and oil companies. A typical assignment for Srivastava goes like this: A mining company has multiple samples from a potential gold mine. Each sample gives a different estimate of the amount of mineral underground. “My job is to make sense of those results,” he says. “The numbers might seem random, as if the gold has just been scattered, but they’re actually not random at all. There are fundamental geologic forces that created those numbers. If I know the forces, I can decipher the samples. I can figure out how much gold is underground.”

Srivastava realized that the same logic could be applied to the lottery. The apparent randomness of the scratch ticket was just a facade, a mathematical lie. And this meant that the lottery system might actually be solvable, just like those mining samples. “At the time, I had no intention of cracking the tickets,” he says. He was just curious about the algorithm that produced the numbers. Walking back from the gas station with the chips and coffee he’d bought with his winnings, he turned the problem over in his mind. By the time he reached the office, he was confident that he knew how the software might work, how it could precisely control the number of winners while still appearing random. “It wasn’t that hard,” Srivastava says. “I do the same kind of math all day long.”

Wired: “Cracking the Scratch Lottery Code”