Joseph Jagger

Joseph Jagger was born in Yorkshire, England, in 1830 and worked as an engineer in the textile mills that powered Britain's Industrial Revolution. His intimate familiarity with mechanical systems gave him unique insight into how machines—including roulette wheels—might develop imperfections through wear and use.

In 1873, Jagger traveled to Monte Carlo with a theory: roulette wheels, being mechanical devices, must have slight imperfections that would cause some numbers to appear more frequently than others. He hired six clerks to record the results of the casino's six roulette wheels over several weeks, then analyzed the data to find biased wheels.

Jagger's approach was purely statistical. After identifying a wheel that favored certain numbers, he began betting heavily on those numbers. Within four days, he had won 2 million francs (equivalent to roughly $5 million today). When the casino moved the wheel to a different position, Jagger identified it by a distinctive scratch and resumed winning.

Jagger pioneered the concept of wheel bias analysis—the idea that mechanical imperfections in roulette wheels could be identified and exploited through systematic data collection. His methods laid the foundation for over a century of advantage play in roulette.

Joseph Jagger's Monte Carlo victory inspired the famous music hall song "The Man Who Broke the Bank at Monte Carlo" (though he is sometimes confused with Charles Wells, who also "broke the bank"). He demonstrated that casino games could be beaten through careful observation and scientific thinking, inspiring generations of advantage players.