This article includes a list of references, but its sources remain unclear because it has insufficient inline citations. (August 2015) (Learn how and when to remove this template message)
Oscar's Grind is a betting strategy used by gamblers on wagers where the outcome is evenly distributed between two results of equal value (like flipping a coin, betting on red or black in roulette, etc.). It is an archetypal positive progression strategy. It is also called Hoyle's Press. In German and French it is often referred to as the Pluscoup Progression. It was first documented by Allan Wilson in his 1965 book,The Casino Gambler's Guide. This progression is based on calculating the size of bets so that in the event of a losing streak, if and when a same-length winning streak occurs, a profit is obtained. The main concept is that there are periods of many wins and periods of many losses. Losses and wins often come in streaks. Ideally, bets are kept low on losing streaks and increased on winning streaks, which hopefully will follow.
Oscar's Grind divides the entire gambling event into sessions. A session is a sequence of consecutive wagers made until 1 unit of profit is won. Each session begins by betting 1 unit, and ends by winning 1 unit of profit. If the gambler loses, the session continues and the bet is repeated. Each time the gambler wins the game following a lost game, the bet is increased by 1 unit. This increase is not performed if the current bet warrants achieving at least 1 unit of profit in total, in case the next game is won. On the contrary, the bet size in such a situation should be decreased to assure exactly 1 unit is won. Given infinite money and time, this makes sure that every session ends with a 1 unit profit.
betsize := 1 profit := 0 REPEAT Bet IF bet_won, THEN profit := profit+betsize IF profit < 1 THEN IF profit+betsize+1 > 1 THEN betsize := 1-profit ELSE betsize := betsize+1 ELSE profit := profit - betsize UNTIL profit = 1
|1||LOSS||-1||Betsize stays the same|
|1||LOSS||-2||Betsize stays the same|
|1||LOSS||-3||Betsize stays the same|
|1||LOSS||-4||Betsize stays the same|
|1||LOSS||-5||Betsize stays the same|
|1||WIN||-4||Betsize is 2 units now|
|2||LOSS||-6||Betsize remains 2 units|
|2||WIN||-4||Betsize increases to 3 units|
|3||WIN||-1||Only 2 units needed to achieve profit|
Oscar's Grind is the same as Martingale-based and Labouchère system in the sense that if you have an infinite amount to wager and time, every session will make a profit. Not meeting these conditions will result in an inevitable loss of your entire stake in the long run. You can only lose 500 times in a row from a 500 unit bankroll, and if occasional wins increase the betsize, this number decreases significantly. Oscar's Grind is based on losing streaks being "compensated" by winning streaks in the short run, and in the example above, a 5-long losing streak was equalised by a 3-long winning streak. If we get 'compensated' with a 5-long winning streak, we get 3 units of profit. The base of the system originates in a hot-hand bias, but winning and losing streaks in gambling have no mathematical ground or proof.
Oscar's Grind can be applied to non-even bets as well ("streets" in roulette or "doubling" in blackjack); one just has to keep track of the amount and increase the betsize after wins accordingly. There are also variations that try to reduce the variance by waiting for a couple of wins before increasing the betsize. As it is with all betting progressions, no variation of Oscar's Grind will make a profit in the long run.
- Mason Malmuth; Lynne Loomis (1993), Fundamentals of Craps, Two Plus Two Publishing, p. 46, ISBN 1-880685-30-2
- "Why Any Progression Must Fail for Negative Expectancy Games in the Long Run?". imspirit.wordpress.com. December 2012. Retrieved 26 August 2015.