Blackjack Insurance – Should You Ever Take It?

Note: This page covers insurance from both a basic strategy and a card counting perspective. Understanding insurance fully requires some familiarity with probability and expected value. For background, see our House Edge guide.

Insurance is one of the most misunderstood bets in live and legal online blackjack. It is offered with regularity, accepted by a large percentage of players — particularly on strong hands — and is almost universally a losing bet in standard play. Yet for card counters in specific situations, insurance becomes one of the most profitable bets available. Understanding insurance clearly means understanding both why most players should decline it and exactly when the math changes. For background on blackjack's rules and structure, Wikipedia's blackjack article covers insurance in context.

What Insurance Is and How It Works

Insurance is an optional side bet offered when the dealer's face-up card is an Ace. The bet is placed in a designated area of the table (above the main betting area, typically marked "Insurance Pays 2:1") and can be up to half the value of your original wager.

The bet pays 2:1 if the dealer's hole card is a 10-value card (10, Jack, Queen, or King) — meaning the dealer has blackjack. If the dealer does not have blackjack, the insurance bet is lost and the main hand continues.

Example:

Main bet: $40
Insurance bet: $20 (maximum = half the main bet)
If dealer has blackjack: You lose the $40 main bet, but win $40 from the insurance bet (2:1 on $20). Net result: $0. Break even.
If dealer does not have blackjack: You lose the $20 insurance bet and play the main hand normally.

The Break-Even Math

For insurance to be a neutral (break-even) bet, the dealer would need to have a 10-value hole card exactly one-third of the time when showing an Ace. Here is why:

If you bet $20 on insurance and the dealer has blackjack one-third of the time, your expectation over three identical situations is:

Win $40 once (dealer has blackjack): +$40
Lose $20 twice (dealer does not have blackjack): -$40
Net: $0

At exactly 1/3 frequency (33.3%), insurance breaks even. Below that frequency, it loses money. The question is: what is the actual probability of the dealer having a 10-value hole card when showing an Ace?

The Actual Probability and House Edge

In a standard 6-deck shoe (312 cards total), there are:

4 Aces (one of which is the dealer's up card — already removed)
96 ten-value cards (10, J, Q, K × 4 suits × 6 decks)
311 remaining cards after removing the dealer's Ace

Probability of dealer having a 10-value hole card = 96 ÷ 311 = 30.87%

The break-even threshold is 33.33%. The actual probability is 30.87%. The insurance bet loses at neutral deck conditions because the probability of the dealer having blackjack (30.87%) is below the threshold needed to make the 2:1 payout worthwhile (33.33%).

Expected value of insurance per $1 wagered:

Win $2 with probability 0.3087: +$0.617
Lose $1 with probability 0.6913: -$0.691
Net expected value per $1: −$0.074

That is a house edge of approximately 7.4% on insurance in a 6-deck game — dramatically worse than the main game's 0.5% edge with basic strategy.

What About "Even Money"?

Even money is a special form of insurance offered specifically when you hold a natural blackjack and the dealer shows an Ace. Instead of waiting for the dealer to check the hole card (which might result in a push if the dealer also has blackjack), the casino offers you an immediate 1:1 payout — even money on your natural blackjack.

Mathematically, taking even money is identical to taking insurance on your blackjack hand. The expected value calculation is the same. At neutral deck conditions:

Declining even money: you win 3:2 (69.13% of the time) or push (30.87% of the time)
Expected value of declining: (0.6913 × 1.5) + (0.3087 × 0) = $1.037 per $1 wagered
Taking even money: guaranteed $1.00 per $1 wagered

Declining even money produces higher expected value ($1.037 vs. $1.00 per dollar). Take even money and you are voluntarily accepting a guaranteed return that is lower than the mathematical expectation of playing out the hand.

Basic strategy says: decline even money. Always.

The Emotional Appeal of Insurance

Understanding why players take insurance despite the math requires understanding the emotional logic. Insurance feels protective. When you have a strong hand — particularly a blackjack itself — the idea of "locking in" a guaranteed win rather than risking a push feels sensible. Loss aversion is a well-documented cognitive bias: people weight potential losses more heavily than equivalent potential gains. Insurance exploits this bias by offering certainty in exchange for mathematical value.

The casino frames insurance as protection. The math frames it as a side bet with a 7.4% house edge. These two framings produce very different behavioral outcomes.

When Card Counters Take Insurance: The True Count +3 Rule

Here is where the analysis gets more nuanced. The insurance bet is not always bad. Its expected value is directly tied to the proportion of 10-value cards remaining in the shoe. As the count rises — meaning more low cards have been removed and the shoe is relatively richer in high cards — the probability of the dealer having a 10-value hole card increases.

When the proportion of 10-value cards in the remaining shoe reaches exactly one-third (33.3%), insurance becomes a break-even bet. When it exceeds one-third, insurance becomes a profitable bet for the player.

In the Hi-Lo counting system, this threshold is reached at approximately a true count of +3. At TC +3 or higher, the shoe is rich enough in 10-value cards that insurance becomes a positive expected value bet.

This is the most valuable and most widely used strategy deviation for card counters. The combination of insurance's large edge magnitude and the frequency with which an Ace appears as the dealer's up card makes this deviation one of the most profitable single plays in the counter's arsenal.

Insurance and Your Hole Cards: A Common Misconception

A common player belief is that holding 10-value cards in your own hand should make you less likely to take insurance (since 10s in your hand reduce the probability of the dealer having one). This is technically correct but irrelevant in practice for non-counters.

At a standard table with other players, you typically see your own two cards and the dealer's up card — not the other players' cards. In a face-up game, you see more cards (which is why it affects composition-dependent strategy slightly), but the net effect is small and does not meaningfully shift the insurance calculation away from the basic conclusion of "do not take it."

For card counters, all visible cards are already incorporated into the running count and true count — so the TC +3 threshold already accounts for whatever cards are showing at the table.

Summary: Insurance Decision Framework

Player Type	Situation	Correct Decision
Basic strategy player	Dealer shows Ace — any hand	Decline insurance
Basic strategy player	Player holds blackjack — even money offered	Decline even money
Card counter	True count below +3	Decline insurance
Card counter	True count +3 or above	Take insurance (max bet)
Card counter	Player holds blackjack, TC +3+	Take even money (equivalent benefit)

Continue to: Blackjack House Edge | Side Bets | Card Counting