Session Risk of Ruin Calculator

Introduction

This page is designed to help you determine the likelihood of losing your entire bankroll during a gaming session based on factors such as your total bankroll, the specific game, the duration of play, and the number of hands played each hour. The tool operates on the premise that if a player finds themselves in the negative at any point before concluding their session, they must leave without any funds remaining, as borrowing is not permitted. Essentially, it guides users on the recommended number of betting units to bring for their gaming experience.

To operate the calculator, first choose a game from the dropdown menu. This selection will automatically fill in the corresponding fields for hands per hour, house edge, and standard deviation. If you believe any of the provided information is not accurate, feel free to adjust those figures as needed. You'll need to manually enter the total hours you plan to play.

Once you've verified that all inputs are correct, press the calculate button, and the tool will provide you with the following insights:

• Total standard deviation = This indicates the level of fluctuation you can anticipate during your gaming session. If you're unfamiliar with the concept, you can disregard this detail.
• Probability of winning: This represents your chances of earning a profit throughout the gaming session.
• Probability of Ruin: This metric reflects the likelihood that a player will exhaust their funds before concluding their desired gaming activities.

Assumptions

• The house edge for blackjack operates under the assumption of six decks being used, the dealer hitting on a soft 17, a payout of 3 to 2 for a blackjack, permission to double down after a split, re-splitting of aces allowed, surrendering is permitted, and the dealer will check for blackjack.
• For roulette, the standard deviation figure is calculated with the assumption that players are only making even-money bets.
• In craps, the calculation presumes that the player is exclusively placing bets on the pass line and taking full 3-4-5x odds.
• All house edge estimates are based on the assumption of employing optimal strategies, with the exception of blackjack, which utilizes basic strategy guidelines.
• In Ultimate Texas Hold 'em, the average bet is considered to be solely on the Ante, rather than combining Ante and Blind bets.
• The house edge for baccarat is calculated based on bets made on the Player.

The methodology for determining the probability of ruin is detailed in Don Schlesinger's 2004 book, Blackjack Attack, on page 132, in the section labeled 'The Short-Term, or Trip, Ruin Formula.' Schlesinger notes that the risk of ruin derived from this formula may be an overestimate, a sentiment my own simulations also support.

Internal Links

• Eternal Risk of Ruin Calculator — This tool estimates the likelihood of ruin within a game where the player has an advantage over an infinite timeframe.
• Gambling Session Calculator .
• The house edge of casino games .

Written by: Michael Shackleford