Blackjack Insurance strategy

Why Blackjack Insurance is never good

The insurance option is portrayed as a way to insure the hand against a possible blackjack for the dealer, but in reality, it’s nothing but a separate bet that is placed on if the dealer’s second card will have a value of 10. This side bet will never have any effect on your chances of winning your original bet and as you’ll always have the odds against you on such a bet it’s never a good option to choose. Let us illustrate this with an example:

If we assume that you’re sitting at a table where only one deck is being used, 16 of the 52 cards will have a value of 10 (four 10s, four jacks, four queens, and four kings). Let’s also assume that the hand you’ve been dealt doesn’t have any of these 16 cards. All of these will then be available in the deck, which has a total of 49 unseen cards as you’ve been given two and the dealer is sitting on an ace. This scenario is the best you could get for insurance, but it still isn’t good enough to be able to profit from it in the long run.

If you would place an insurance bet of £1, you would win £3 every time the dealer is turning over a 10 or a face card. Should you play out this scenario 49 times, you would on average win 16 of them as there are 16 winning cards and lose the remaining 33 as there are 33 losing cards. Every win would result in a net profit of £2 (£3 win – £1 bet), which on all 49 scenarios on average would win you £32 (16 winning hands * £2 net profit). Every losing hand would be a loss of your £1 bet, which in total would be £33 (33 losing hands * £1 bet).

As your total win turned out to be £32 and your total loss £33, you would end up with a net loss of £1 (£32 – £33). This means that you’ll on average lose £1 for every £49 that you bet on insurance, which is equal to a 2% loss (1/49). In other words, for every hand you’re playing with insurance you’re on average losing 2%, provided that you’re not holding any 10 or face card in your hand. If you did the percentage would be a lot higher.

Let’s assume that the hand you were dealt was 10 – 10 and you chose to insure it. In such a scenario only 14 of the 49 unseen cards would be 10s or face cards. This means that if you play out this scenario 49 times your total win would on average be £28 (14 winning hands * £2) and your total loss £35 (35 losing hands * £1 bet). This scenario would result in an average loss of £7 (£35 – £28) for every £49 that you bet on insurance, which is a loss that’s equal to 14,3% (7/49).

The only way that insurance could be advantageous to use is if you would know that more than a third of the unseen cards are either 10s or face cards. In such a case it would over time in fact always be profitable to use the option as the blackjack odds would be in your favour.