Blackjack Risk of Ruin

It’s wise to know the risks of losing set amounts of money when playing Blackjack games. The more you know about the risks you are taking at the table, the easier it is to control the amount you can potentially lose (or hopefully win) from one session to the next. This article will cover the basics of the “risk of ruin” in Blackjack to help you understand how you can minimize, or increase, the risk involved the next time you sit down at the Blackjack table.

What is risk of ruin?

Risk of ruin is the percentage likelihood of losing a set amount of money over a specific number of hands at the Blackjack table. Ruin is just a way of saying “going broke”. For example, if you decided to take a $100 bankroll and bet $1 on each hand for 100 hands, your risk of ruin would be 0.5% (or a 1 in 200 chance of going broke).

I’ll show you how I worked this out in a moment.

Why learn about the risk of ruin?

Risk of ruin is perfect if:

  • You want to stay in control of risk as much as possible.
  • You want to know the varying risk for different bet sizes and number of hands.
  • You want to clear bonus play-through requirements as quickly but as safely as possible.

Almost every gambler takes risk of ruin in to account when they place their bets, providing that they are sober of course. This article is simply going to help you put some numbers to that intuition.

Win Rate ($/hour)
Standard Deviation ($/hour)
Bankroll ($)
Results: % chance of ruin

The Blackjack risk of ruin table.

  • The risk of ruin column is on the left.
  • The number of hands row goes along the top.
  • The centre numbers show the number of betting units. (Don’t worry; I’ll explain all of this very soon.)

Risk of Ruin Blackjack Charts


Risk
of Ruin
Number of Hands to Play
100 200 300 400 500 600 700 800 900
50% 7 11 14 16 18 20 22 24 25
40% 9 14 17 20 23 25 27 29 31
30% 12 17 21 25 28 31 33 36 38
20% 15 21 26 31 34 38 41 44 47
10% 19 27 34 39 44 48 53 57 60
5% 22 32 40 46 52 58 62 67 71
4% 23 34 42 49 55 60 65 70 75
3% 25 36 44 51 58 64 69 74 79
2% 27 38 47 55 62 68 74 79 84
1% 29 42 52 61 68 75 82 88 93
0.5% 32 46 57 66 74 82 89 95 101
0.25% 35 50 61 71 80 88 96 102 109
0.1% 38 54 67 77 87 95 104 111 118
0.01% 45 64 79 91 102 112 122 131 139

Risk
of Ruin
Number of Hands to Play
1000 1200 1400 1600 1800 2000 2500 3000
50% 27 30 32 35 37 40 45 50
40% 33 37 40 43 46 49 56 62
30% 41 45 49 53 56 60 68 75
20% 50 55 60 65 69 73 83 92
10% 64 70 76 82 88 93 105 116
5% 76 83 90 97 104 110 124 137
4% 79 87 95 102 108 114 129 143
3% 83 92 100 107 114 121 136 151
2% 89 98 107 114 122 129 145 161
1% 99 108 118 126 134 142 160 177
0.5% 107 118 128 137 146 154 174 192
0.25% 115 126 137 147 156 166 187 206
0.1% 125 138 149 160 170 180 202 223
0.01% 148 162 175 188 198 212 236 261

Both risk of ruin tables were originally published on the Wizard of Odds blackjack risk of ruin article.

The 3 variables involved with risk of ruin in Blackjack.

Whenever you work out risk of ruin in Blackjack, there are 3 variables you need to consider.

1.   The number of betting units (this is just your bankroll divided by bet size).
2.   The set number of hands to be played.
3.   The risk of ruin.

As long as you know at least 2, any 1 of the 3 remaining variables can be worked out using the table above.

Example 1: Working out your risk of ruin.

Let’s say that you have a $200 bankroll and you want to play 300 hands whilst betting $5 on each hand. You now decide that you want to work out your risk of ruin for this session.

By betting $5 on each hand with our $200 bankroll, we have 40 betting units in total ($200 / $5). Now we have 2 our variables, we can figure out our risk of ruin from the table.

Firstly we look across the top row to find the number of hands we wish to play (300, remember?). We then look down this column to find the betting units closest to 40. Luckily 40 is perfectly set in the table there already, so we can look across to the left to the risk of ruin column and see that our risk of ruin for this session will be 5%.

Easy stuff really. All you need to know is 2 variables/numbers from the table and you can work out your risk of ruin, the number of hands you should play or the number of betting units required.

Example 2: Working out your ideal betting units.

A more probable situation is where you want to control your risk of ruin before you play. So for example, let’s say you have a $1000 bankroll and you want your risk of ruin to be 1% over 500 hands. How big should your bets be?

If we look at 500 hands and the 1% risk of ruin on the table, it tells us that we should have 68 betting units behind us to achieve these figures. So what’s 68 betting units from $1000?

Easy, just divide $1000 by 68 and we get $14 (or $14.7 to be precise). Therefore to play 500 hands with just a 1% risk of ruin, we should only bet $14 on each hand we play.

Evaluation of risk of ruin in Blackjack.

Risk of ruin applies to all forms of gambling, whether it’s; Sports Betting, Texas Hold’em Poker, Bingo or Casino games like Blackjack (of course).

Even though we all subconsciously work out rough ideas of the risk of ruin in our heads, it’s far better to have solid numbers to work with so that we can be more precise with the money we are putting at risk. The last thing any of us want is to be surprised by losses that we never could have expected.

I realise that I’ve left out an example for working out how many hands you should play if you have a risk of ruin in mind and have already worked out your ideal betting units, but it should be fairly easy to figure out if you understood the first two examples.

The mathematics involved with risk of ruin may look a little intimidating at first, but trust me when I say that it’s so much easier than it looks if you spend a little time working with it.