Martingale Gambling System
Negative progression system, the oldest known system.
The Martingale system is a very old and extremely simple system. It is based on the probability of losing infinite times in a row and is usually applied to 'even money' bets.
You start with one bet. If you win, you start again with one bet. If you lose, you double your bet. Each time you lose, you double your last lost bet. Eventually you are bound to win. When you win you recover all of your lost bets plus one unit profit against your initial wager.
Although infallible in theory, the Martingale system requires a large bankroll, has a very low return and is a very risky one because of the maximum bet limits imposed by the casinos. If you run out of money or reach the house limit, you can lose a lot with no chance to recover your losses.
The Ormond System
Negative progression, a variation of the Martingale System.
Assumes you will win before you reach the house limit and can bankroll the losing run. Bet an initial amount (A). For each win, on the next bet A again. For each loss, bet A*x + A where x is the number of losing bets. Thus if you finally win, you will recover all bet money, plus A for every loss. The progression would look like this on a $5 table: 5, 15, 35, 75, 155, 315, etc. As with all negative progressions, and this one even more so, it requires more capital and is employed to force a winning outcome following a losing streak.
Anti-Martingale System
Positive progression.
Remarks: Pre-decide a win goal, say 7 units.
Bet on red. If you win, leave the two on red (or switch to black if you feel like it). If you win again, leave the four on another even chance. If you win the third in a row, skim the seven and restart with one. Every time you lose, restart with one.
Negative progression betting systems: You increase the bet when you lose. They require more capital and are usually employed to force a winning outcome following a losing streak. (Avoid these systems if you can; they will not do your nerves any good and they are painful when you lose.)