For as long as games of chance have existed, people have tried to find an edge. Some have relied on superstition, while others have hunted for quick-and-easy schemes. The top gamblers, however, have often turned to science. By combining academic theory with ambition and focus—plus a good dose of audacity—they have managed to exploit loopholes that nobody even knew existed. But how did they do it?

One tactic is to use sheer brute-force effort. In this respect, few could rival the wager Stefan Klincewicz and 27 collaborators carried out in May 1992. Their target was the Irish National Lottery, and their motivation was a simple mathematical calculation. They’d noticed it would cost about £1 million to buy up every possible combination of lottery numbers, which would by definition include the winning ticket. So if the jackpot was big enough—as it was in the £1.7 million May rollover—they could in theory buy their way to victory.

Unfortunately, reality proved a little trickier. To carry out their plan, the team needed to make more than a million ticket purchases, with each one filled out by hand. Plus, they had to win a cat-and-mouse game with lottery officials, who were trying to stop them. Still, it was worth the effort: When the draw was made, they netted a £300,000 profit. They were not the first to win this way. In 1729, Voltaire made his fortune by taking advantage in a similar flaw in a Parisian lottery.