Should You Take Insurance in Blackjack? The Math and the One Exception
Insurance is offered every time the dealer shows an Ace, and it sounds like protection. In a normal 8-deck shoe it is simply a losing side bet — with one exception that only a count can see.
What insurance actually is
When the dealer's up card is an Ace, you may put up to half your bet on insurance. It pays 2 to 1 if the dealer's hole card is a ten-value card (10, J, Q or K) and loses otherwise. It is a separate bet on one card — it has nothing to do with how good your own hand is. Taking "even money" on your blackjack is the same bet in another form.
The break-even point
A bet that pays 2 to 1 breaks even when it wins one time in three, so you need more than 33.3% of the remaining cards to be ten-value.
| Situation (8 decks) | Ten-value cards left | Insurance |
|---|---|---|
| Fresh shoe, dealer shows an Ace | 128 of 415 = 30.8% | Loses about 7.5% of what you put on it |
| Break-even | 33.3% | Neither wins nor loses on average |
| Hi-Lo true count about +3 or higher | above 33.3% | Worth taking |
So the rule card counters use is short: take insurance only when the true count is +3 or higher; otherwise always decline. That is the threshold built into CountPilot's insurance prompt.
"But I have a good hand"
A strong hand like 20 does not make insurance better. The insurance bet only cares about the hole card. The one small link is that tens in your own hand are tens that are not in the shoe — which is exactly what the count already measures.
When the count is close to +3
Every count has some uncertainty. If the true count shows +3.1 with a ± range that reaches below +3, the decision is close either way — and near the threshold, the cost of being slightly wrong is small. Far below +3, declining is clearly right.
Does the dealer check for blackjack?
On the Playtech live tables we recorded, the dealer checked the hole card when showing an Ace — a dealer blackjack ended the round at once — but not when showing a ten. Rules differ between tables, so CountPilot lets you set this in its table settings.
Check that counting aids are allowed where you play — many casinos' terms prohibit them.
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