Blackjack Insurance: Should You Take It?

The short answer

Decline insurance. The bet loses money with any number of decks, unless you count cards and know that more than a third of the cards left in the shoe are tens. In a 6-deck shoe, with no ten in your first two cards, a $50 insurance bet on a $100 hand loses $3.40 on average.

Even money is a separate offer, made when you have a blackjack and the dealer shows an Ace. At a table that pays 3:2 for blackjack, decline it. There it is the same bet as insurance on your blackjack, and in a 6-deck shoe it pays $3.88 less per $100 than waiting for the dealer to check. At a table that pays 6:5, a fixed 1:1 payment is worth $16.89 more per $100 than declining, in the same shoe. Insurance on your blackjack is still worth less than declining at 6:5, so ask which of the two the table offers.

All the numbers on this page are for a hand from a full shoe, where the only cards you know are your own two and the dealer's Ace. Here, even money means that offer on your blackjack. It is not the 1:1 payout on a 21 made from a split Ace.

What insurance costs

The insurance bet is half your main bet. Here is its average result on a $100 hand, in a 6-deck shoe, by the number of tens in your first two cards:

Only the number of tens in your hand changes the result, because insurance wins only when the dealer's hidden card is a ten. A 9+7 and a 2+3 give the same numbers.

Why insurance loses

Insurance pays 2:1, so it breaks even only when exactly one card in three is a ten. A full deck has 16 tens in 52 cards, which is already fewer than one in three. The cards you can see change that share, and on a hand from a full shoe it never reaches one in three. With the dealer's Ace and your two cards out of a 6-deck shoe, and no ten among your cards, 96 of the 309 unseen cards are tens (31.07%). In a single deck it is 16 of 49 (32.65%), closer to one in three and still below it. Each ten in your own hand takes one more ten out of the shoe.

At a European no-hole-card table the dealer takes the second card only after you play. When you decide on insurance, that card is still equally likely to be any card you have not seen, so the insurance numbers on this page apply there too.

Even money with a blackjack

When you hold a blackjack and the dealer shows an Ace, your blackjack pushes if the dealer has blackjack too. So insurance on your blackjack returns exactly your bet when the dealer has it: the main hand pushes, and the insurance pays 2:1 on half a bet. Here is each choice per $100 bet, in a 6-deck shoe:

Declining is an average, and so is insurance on your blackjack at 6:5. The other values are the same on every hand.

At 3:2, insurance on your blackjack and a fixed 1:1 payment both pay $100 on every hand, and declining is worth $3.88 more on average. At 6:5 the insurance bet costs the same $3.88, but a fixed 1:1 payment beats declining by $16.89. If you play at 6:5, ask whether the offer is a fixed 1:1 payment or an insurance bet on your blackjack, because only the fixed payment is worth taking. The house edge guide shows what the 6:5 payout costs you on every other hand.

Does the number of decks matter?

With no ten in your first two cards, fewer decks bring insurance closer to break-even, and it still loses:

With a ten in your first two cards it goes the other way, and fewer decks make insurance lose more. A single deck has only 16 tens, so a ten in your hand takes a larger part of them out of the shoe than it does in 6 or 8 decks.

When insurance can pay

Insurance is a good bet only when more than a third of the cards left in the shoe are tens. On a hand from a full shoe that never happens. Later in a shoe it can, after many small cards have been played, and only a player who counts cards knows when. If you do not count cards, decline insurance every time.

How we got these numbers

We computed every number on this page ourselves. Insurance is an exact count: take your two cards and the dealer's Ace out of the shoe, count the tens that are left, and the value of a bet that pays 2:1 follows. The even money values add the main hand, settled after the dealer checks for blackjack. We checked every average on this page with a simulation of 2 million hands each, and every simulated result landed within 5 cents per $100 of the exact one. Assumptions: the dealer checks for blackjack, your blackjack pushes a dealer blackjack, and the shoe is reshuffled before each hand.