The article discusses the d'Alembert betting system, one of the most popular systems used in casinos in the 19th century. While the systems appear to guarantee success by equalizing wins and losses over time, they fail to account for the risk of running out of money before wins and losses balance out. However, the systems can provide surprisingly high returns on investment when wins do occur, obscuring the overall negative expected value. The article analyzes how systems like the d'Alembert are seductive due to the potential for large gains despite the inevitability of overall losses in the long run.