The martingale family of systems is the most popular negative-progression system sold in books and on websites. The basic version asks the player to double the stake after each loss, then return to the starting stake on a win. A single win at any point in the sequence recovers all prior losses and returns a profit equal to the starting stake. The maths of the family are tidy; the practical flaw is equally tidy.
The flaw is geometric. A one-unit starting stake becomes 2 after one loss, 4 after two, 8 after three, 16 after four and 1024 after ten. A 1024-unit stake on a 1-unit starting bankroll is a stake the bankroll cannot cover. The table maximum exists precisely to interrupt this growth; the practical floor on the bet size is the point at which the next double is unavailable. No published martingale removes that floor.
The anti-martingale
The anti-martingale asks the player to double the stake after each win and reset after each loss. It is the symmetrical cousin of the basic martingale. The mathematics are the mirror image: a long winning streak at the start of a session produces a very large stake, but a single loss at any point returns the player to the starting unit. The anti-martingale rewards concentration of the bankroll during winning runs but does not change the per-spin expectation.
The d'Alembert and the Fibonacci
The d'Alembert progression asks the player to add one unit after a loss and subtract one after a win. The Fibonacci progression asks the player to step forward in the Fibonacci sequence after a loss and step back two places after a win. Both systems reduce the rate of stake growth compared to the martingale, but neither removes the edge. The smaller growth rate produces smaller reward per recovery, which means more recoveries to clear the same loss. Over a long sample the per-spin expectation is unchanged.
The honest summary
No negative progression reverses the house edge. The systems change the shape of a session — the size of the bets, the duration of losing runs, the size of winning runs — but the average return per spin is fixed by the wheel and the payouts. An adult reader who treats these systems as entertainment budgets rather than as edge-beaters will be reading them correctly.