In gambling, a system is a set of rules a player follows to decide how much to stake on each bet, usually by raising or lowering the amount after a win or a loss. Well-known examples include the Martingale, the D’Alembert, the Labouchère and the Paroli, and which one suits a player depends on the game being played.
The systems differ mainly in what triggers a change. The Paroli tells you to double your stake after each win until you have won three times in a row. The D’Alembert moves more gently: add one stake after a loss and take one away after a win. Nearly all systems are built on simple arithmetic and aim to give the player an edge over the casino or sportsbook.
Why operators should understand systems
No staking plan changes the odds of the game underneath it; it only reshapes the pattern of wins and losses. Progressive systems drive stakes up quickly during losing runs until they meet the table limit, and doubling-after-loss patterns are a useful signal for player-protection monitoring.