The D'Alenbert system: (Money management betting systems, gambling systems.)
Negative progression and insurance system.
This is a mixture of Martingale and Insurance systems. Bets are raised one unit after each losing bet and lowered one unit after each winning bet. The sequence and amount raised or lowered can be varied to suit particular games and odds.
* Negative progression betting systems: You increase the bet when you lose. Require more capital and usually employed to force a winning outcome following a losing streak. (Nerve-wracking, very painful when you lose. Avoid these systems if you can.)
* Insurance betting systems: You decrease the amount of your bet when you win, usually following a high initial bet or following short 'let-it-ride' progressive wins. (Play it safe. A good compromise.)