As one of the most exciting casino games for spectators, roulette has been a mainstay of modern casino floors since the creation of the roulette wheel in 18th century France. While the rules and wheel designs have varied throughout the games history, the modern day roulette wheel consists of 36 alternating black and red pockets, each marked with a number from 1 through 36, as well as one or two additional green pockets marked with zeros. The wheel is spun and a ball, spun in the opposite direction, jumps around the pockets until it eventually settles on the winning pocket for that round.

As with other casino games of chance, the game of roulette is designed and played in most modern casinos with a distinct albeit modest edge for the house. The actual advantage the house enjoys will vary slightly depending on the number of green, zero-marked pockets on the wheel, as determined by the wheel type in question. Traditional American roulette wheels feature two green zero pockets, giving the house a mathematical 5.26% edge, while European wheels utilize only a single green zero, dropping the house edge down to 2.70%.

Since roulette is inherently favored for the house, most players tend to focus on betting techniques or mechanical flaws to try to eke out their own advantage. One very famous player was the British engineer Joseph Jagger, who is among the most successful and publicly known roulette winners in history. Jagger’s plan was both devious and ingenious, ultimately proving incredibly successful during the short period with which he employed it.

Jagger hired six accomplices in 1873 to secretly record the outcomes of the roulette wheels at the Beaux-Arts Casino in Monte Carlo. After enough time passed to allow proper analysis, Jagger discovered that one wheel in particular which had a notable scratch in it was producing far more pocketed balls on nine numbers in particular: 7, 8, 9, 17, 18, 19, 22, 28 and 29. On traditional European roulette wheels such as the flawed wheel in question, a whopping six of these nine biased numbers appear in consecutive sequence: 9-22-18-29-7-28.

Beginning July 7th, 1875, over the course of the next three days, Joseph Jagger was able to earn the equivalent of $4.8 million today! As his winning streak became recognized by the casino, wheels were shuffled around to different tables and even the metallic frets dividing the pockets were swapped frequently. These measures lead Jagger to a significant losing streak for a period before bouncing back a bit, seesawing his winning and losing over the next two days until July 12th, 1875, when Jagger elected to cut his losses and left Monte Cristo with the equivalent of around $5.5 million.