Find out what the blackjack insurance bet is and get your head around the situations in which it may or may not be the right move

What is insurance in blackjack? Blackjack insurance is a side bet offered to the player if the dealer’s up-card is an ace, as insurance against the dealer’s hand being ‘blackjack’.

Blackjack insurance odds pay out at 2/1 and the maximum bet allowed is generally half of the player’s main bet. 

This potentially offers the player the chance to break even on the hand in the eventuality that the dealer has blackjack, even if losing their main bet.

Insurance is offered before the dealer checks their hole card (the one not initially visible to players) and paid out should the hole card have a value of 10, making a two-card 21.

When to take insurance in blackjack

Insurance can seem like an attractive option for the player if the dealer’s up-card is an ace, as there is a close to a one-in-three chance their other card has a value of 10. 

However, probability suggests that insurance is likely to be a losing bet in the long term, unless you are a very capable card counter. 

You need the dealer to have a 10-value card as his hole card to win your insurance bet. Expert card counters can keep track of the amount that are still in the deck and ascertain when there are enough to make insurance the percentage call.

Why insurance should generally be avoided in blackjack

The following example shows why, even in a best-case scenario such as the one below, betting blackjack insurance is a losing strategy in the long run.

1. You are playing alone against the dealer in a one-deck game and neither card in your initial hand has a value of 10.
2. This means 16 of the remaining 49 cards have a value of 10, giving your £10 insurance bet the highest possible chance of winning.
3. Despite this, your position remains one which is not likely to be possible in the long term. 
4. On average the £10 insurance bet wins 16 times and loses 33 times. Each win pays £20 profit, making a total of £320.
5. However, the 33 losses at £10-a-time leaves you £10 down overall.

This hand is a best case scenario because neither you, nor any other players have 10-value cards in their initial hands. If this was the case, the chance of the dealer having a 10-value hole card (and therefore you winning your insurance bet) would be even lower.

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