Should You Ever Take Insurance in Blackjack?
No. Insurance pays 2 to 1, but in a 6-deck game the dealer has a 10 under the ace only about 31% of the time, and you need 33.3% to break even. In 1.5 million simulated hands with House21's rules, insurance returned -7.6% of every chip put on it. The one exception is for card counters at a very high count, and almost nobody is in that situation.
What insurance is
When the dealer's face-up card is an ace, you're offered insurance before anyone plays. It's a separate side bet of half your original bet that the dealer's hidden card is a 10, jack, queen or king, making blackjack.
- If the dealer has blackjack, insurance pays 2 to 1. You lose your main bet, so overall you break even on the hand.
- If not, you lose the insurance and the hand plays on as normal.
At House21 you have 8 seconds to decide.
Why 2 to 1 isn't enough
A 2 to 1 payout is fair only if the dealer has blackjack one time in three. A 6-deck shoe has 96 ten-value cards out of 312. Once you can see the dealer's ace and your own two cards, the chance of a 10 underneath depends a little on what you hold:
| Your two cards | Ten-value cards left | Chance the dealer has blackjack | Result per 100 chips of insurance |
|---|---|---|---|
| No 10s (e.g. 7,5) | 96 of 309 | 31.1% | -6.8 chips |
| One 10 (e.g. 10,6) | 95 of 309 | 30.7% | -7.8 chips |
| Two 10s (e.g. K,Q) | 94 of 309 | 30.4% | -8.7 chips |
Notice the bottom row. The hand people most want to protect, a 20, is the one where insurance is worst, because your own cards took two 10s out of the shoe.
Our simulation of 1.5 million hands where the dealer showed an ace landed at -7.6%, right in the middle of that range.
"Even money" is the same bet
If you have blackjack and the dealer shows an ace, some tables offer "even money": take a guaranteed 1 to 1 payout now instead of risking a push. Taking insurance on a blackjack does exactly the same thing.
It feels safe, but it costs you. If you decline, your blackjack pays 3 to 2 unless the dealer also has blackjack (a push). With 95 tens left among 309 cards:
| Choice | Average result per 100 chips bet |
|---|---|
| Take even money | +100 chips, guaranteed |
| Decline | +103.9 chips on average (150 chips 69% of the time, your bet back 31%) |
Decline and you earn about 4% more over time. The guarantee is what you pay for.
"But insurance protects my good hands"
It doesn't protect them; it adds a second, losing bet next to them. When the dealer has blackjack, the insurance win and your hand's loss cancel out. When the dealer doesn't, which is about 69% of the time, you've given away half a bet. Your good hand was going to win or lose on its own merits either way.
The one case where insurance pays
Insurance becomes a winning bet when more than a third of the cards left in the shoe are 10s. That only happens deep in a shoe after many low cards have come out. Card counters using the Hi-Lo count take insurance when the true count reaches about +3. Without counting you can't tell when that is, so the rule for everyone else stays simple: decline. More in Does card counting work online?
Common questions
Does the dealer check for blackjack before I play? Yes. At House21, after insurance closes, the dealer checks. If it's blackjack, the round ends and you lose only your original bet (or push with your own blackjack).
Is insurance offered when the dealer shows a 10? No. The dealer still checks for blackjack, but there's no side bet.
Does it matter how many players took insurance? No. Each player's insurance is a separate bet with the same odds.
All other plays are in the basic strategy chart.