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✔️ USA Players Welcome

As you become more skilled and informed in the art of card counting you are likely to encounter a concept known as Risk of Ruin (ROR). While many blackjack authors have written extensively about the subject and described it in terms of complex mathematical equations, risk of ruin can be simply described as your chance of doubling your bankroll versus busting out during a blackjack session. Remember, R.O.R. is part of card counting just as the following: Edge Sorting, Hole Carding, Shuffle Tracking, Wonging in Blackjack, Camouflage Betting, Team Play, & Betting Spread.

It can be a tricky subject to handle and one that is rife with misconceptions but understanding the basics of ROR will make you a better player in the long run and increase your chances of making a profit.

What is risk of ruin, really?


If you want to be very basic about it the risk of ruin is the risk of going broke. For a professional blackjack player losing an entire bankroll is the kiss of death. Without a bankroll you can’t get in the game, and without getting in the game you can’t win. Therefore, a concept such as risk of ruin which is meant to quantify the numbers and percentages of that possibility happening in a blackjack session is a useful piece of ammo in the card counter’s arsenal of weapons.

Try to think of it in the most basic terms before we explore the mathematical side of things: what is the chance that I will lose my entire bankroll during a single session of blackjack. What is the chance that I will double it?

You should be able to see right away that this is a subjective subject. The truth is that you should never suffer “Gambler’s Ruin” at blackjack or any other gambling game because at no time should your entire bankroll be at risk in a single session. You can’t lose everything if everything is not in play. That is why we emphasize sound bankroll management as the most important blackjack strategy.

Understanding the numbers

Take a look at the following numbers. They can be just a little bit depressing:

Bankroll versus Probability of Doubling

(In Units)

  • 10—48.11 %.
  • 20—46.33%.
  • 50—40.66%.
  • 100—31.95%.
  • 200—18.06%.

As you can see by these numbers, based on those given by Don Schlesinger in his blackjack book Blackjack Attack, your chances of doubling your bankroll actually goes down the larger your bankroll becomes. But wait, you say. Haven’t you said many times that a bigger bankroll gives me a better chance of winning at blackjack? Yes, of course it does, but the problem here is with the approach of trying to double your money during each session.

Let’s take a look at what happens if you use a 50-percent win limit as we have suggested before on the Counting Edge website. In that case your chance of having a winning session soars to 64.12 percent when you begin with 20 units.

The evidence is somewhat clear: a bigger bankroll won’t necessarily lessen your odds of risk of ruin but a wise bankroll management strategy will.

Bigger win goals, not a bigger bankroll = bigger risk

Blackjack is a negative-expectation game. In simple terms this means that for x amount of hands you play you can expect to lose x amount of dollars. This is how the casinos make money. Without getting into a deep discussion of the house edge let’s just assume that a typical blackjack player is at a 2 percent disadvantage (that number can be much higher if the player does not stick to basic strategy or plays side bets and other gimmicks). For every dollar bet the house returns ninety-eight cents in winnings, giving them a profit of two cents on every dollar. With property strategy and card counting you can cut that number to 0.5 or even a little less but eliminating the house edge completely is nigh impossible.

Therefore, you must first understand that the risk of ruin is present each time you sit down at the blackjack table. It only makes sense that the bigger your bankroll is the more you have to lose and therefore your personal risk of ruin is greater. With a bigger bankroll, however, you also have a chance to win more.

An inherent problem with the Risk of Ruin concept is that is presupposes you will lose. You are basically asking yourself how long you can play before going broke. While we understand the advantage of knowing this from a standpoint of creating a bankroll management strategy, your goal should not be to log hours at the table but to win. Winning can be accomplished within fifteen minutes of sitting down at the table. So can losing if you manage your money improperly.

To truly counteract risk of ruin you need to satisfy yourself with smaller win goals and build your bankroll over time.


  1. Why is ROR important for blackjack players?
    • ROR helps players determine how much of a bankroll they need to withstand the natural swings or variance in the game, ensuring they don’t go broke before they have a chance to profit from their edge.
  2. How is ROR calculated?
    • ROR is calculated using complex mathematical models that consider factors like the player’s advantage, bet spread, and bankroll. There are various formulas and software tools available to assist in this calculation.
  3. Does a lower ROR mean a player is guaranteed not to lose their bankroll?
    • No, a lower ROR just means there’s a smaller chance of losing the entire bankroll. Even with a 1% ROR, there’s still a 1 in 100 chance of losing the whole bankroll.
  4. How does card counting influence ROR?
    • Card counting provides players with a varying advantage over the house. Understanding this advantage and how often it occurs is essential in calculating a card counter’s ROR.
  5. Can ROR be reduced to zero?
    • While players can reduce their ROR by adjusting their betting strategies or having a larger bankroll, it’s virtually impossible to eliminate it entirely due to the inherent variance in the game.
  6. How does bet sizing influence ROR?
    • Larger bets relative to one’s bankroll increase ROR. To decrease ROR, players can reduce their bet sizes, especially during negative counts, or increase their overall bankroll.
  7. Should all blackjack players be concerned with ROR?
    • While it’s particularly vital for advantage players like card counters, any player who wishes to manage their bankroll and play sessions effectively should understand their ROR.
  8. How does game variation and rules affect ROR?
    • Different blackjack rules and conditions, such as the number of decks, payout ratios, and dealer actions, can affect the house edge and a player’s advantage, which in turn impacts ROR.
  9. Are there tools or software available to help calculate ROR?
    • Yes, several software tools, often used for card counting training or blackjack simulations, can also calculate ROR based on various game conditions and player strategies.

Understanding ROR is crucial for serious blackjack players. It provides insight into the balance between maximizing potential returns and managing the risk of significant losses. Proper bankroll management, informed by an understanding of ROR, can make the difference between a profitable session and going bust.

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