Roulette is a game that has been designed for the specific purpose of turning a reliable profit for the casino. The green zero pockets, upon which no outside bets can be placed, ensure that the house has a statistical edge over the players. Legendary theoretical physicist Albert Einstein was once reported to have said, "You cannot beat a roulette table unless you steal money from it". Yet, over the years, countless gamblers have ignored Einstein's sage words and employed a myriad of betting systems and strategies in an attempt to overcome the house edge in roulette.
Virtually every roulette strategy is based on the mistaken belief that past results have a bearing on future results. For example, you might think if a number has come up recently it will be less likely to come up again soon. In reality, the chances of that number coming up again soon are completely unaffected by previous results. Every time the wheel is spun, the odds for a particular result are exactly the same. While it is possible to win large sums of money using a betting system, it is much more likely that you will lose more than you win.
Perhaps the most famous early example of a big win with a betting system was Charles Wells in 1891, whose exploits were immortalised in the song 'The Man Who Broke The Bank At Monte Carlo' the following year. Wells was a swindler and petty crook who famously cleaned out several roulette tables at the Monte Carlo casino in Monaco over the course of a week. At the time, he claimed that his big wins were the result of his engineering expertise, and used his fame to extract huge sums of money from investors looking to benefit from this expertise. However, despite some big wins, he lost virtually all the money that he had been given to gamble on behalf of the investors, and later admitted that his big wins were merely a combination of luck and faith in the risky Martingale betting system, which can lead to big wins, but is much more likely to lead to large losses.
However, there have been a few people over the years that have been able to put their mathematical and engineering expertise to good use at the roulette table. For example, in 1873, a Brit called Joseph Jaggers, along with six assistants, made detailed observations of all the roulette wheels at the Monte Carlo casino, and found one that had a significant bias towards certain numbers. Using this knowledge, Jaggers and his team managed to make $325,000 from this crooked roulette wheel, a huge amount of money at the time. In the early 90s, Gonzalo Garcia-Pelayo essentially pulled off a high tech version of the same trick, recording results over time and analysing them with a computer to determine which numbers the wheels were biased towards. He won over a million euros using this method. Because of events such as these, casinos have been monitoring the performance of their wheels a lot more closely in recent times, and there have also been several changes to the basic design of the wheel over the years in an attempt to ensure that such tactics will not succeed in future.