Garcia-Pelayo is not your average roulette player. In the early 1990s, this Madrid native discovered that certain roulette wheels were not completely random. In fact, they were biased. Because of small imperfections -- tiny flaws in the roulette wheel's gears, differences in the sizes of the pockets, or even an unlevelled floor -- some numbers tended to come up more often than others. Garcia-Pelayo painstakingly recorded the winning numbers on thousands of spins, then conducted a statistical study on this raw data.
By continuously betting on the numbers that his analysis showed came up most often, Garcia-Pelayo turned a 5% disadvantage into a near 15% advantage over the powerful casinos of Europe. What can an individual do with such a favourable proposition? Well, over a span of a just a couple of years, Garcia-Pelayo and his family exploited this edge to win more than two million euro.