Research Paper · Theodoros Karras · 2025-05-28
Mathematical Properties of the Fibonacci Betting Progression
The Fibonacci progression is often proposed as a 'safer' alternative to the Martingale. We examine its mathematical properties under realistic table limits and bankroll constraints. The progression delays ruin but does not avoid it, and its expected value remains strictly negative. However, the distribution of outcomes has interesting tail characteristics that merit explicit description.
The Fibonacci progression raises the next bet to the sum of the previous two after a loss. Proponents argue it dampens the exponential growth characteristic of Martingale.
We derive closed-form expressions for the probability of ruin across a range of session lengths and table limits, and we verify the analytical results via one million simulated sessions.
Our results confirm that the Fibonacci progression does reduce the probability of rapid ruin but does not change the underlying expected value. Under realistic table limits, the probability of encountering the ceiling within a thousand-spin session is non-trivial.
We do not recommend progression systems to newcomers. We do think they deserve careful study by anyone curious about how constrained risk-seeking interacts with a wheel of modestly negative expected value.