In the game of blackjack, whether you’re playing online blackjack or at a brick and mortar casino, you and the house have the same goal. That goal is to make money. Unfortunately, those goals are mutually exclusive. They can’t both occur at the same time. If you win money, the casino loses money and vice versa. For that reason, you need to keep in mind that while the dealer should be trusted, his interests are not the same as your own.
There are a lot of rules and decisions that are beneficial to the player, such as splitting and doubling in the correct situations. Unless you ask for help, though, the dealer won’t remind you to do that. The dealer probably won’t say, “You have a pair of sevens. Would you like to split them?” It’s up to you to know that you should split a pair of sevens.
However, there is one decision that the dealer will always ask you about and that is insurance. If the dealer has an ace as an up card, he will ask if you want to buy insurance against a blackjack. Not only that, but “Insurance pays 2 to 1” can usually be found printed right on the blackjack table, just to remind you. Is that out of the kindness of his heart? Hardly. The dealer is quick to ask about this because insurance is a bet with a high house edge. You’ll notice that the table doesn’t have “You should always split aces” printed on it.
Insurance is a suckers bet and you shouldn’t take it. For those who don’t know much about the rule, insurance is offered when the dealer has an ace as an up card, because in that case if he has a 10 in the hole, he has a natural blackjack and you would always lose unless you also have a blackjack. The dealer then offers insurance where you get paid 2 to 1 if he does have a blackjack and if he doesn’t, he wins that side bet and can also win the original bet if he still beats your hand.
Therefore, insurance is basically a bet that the dealer has a 10 in the hole. While there are more cards with a value of 10 than any other value, you need to remember that it’s still outnumbered. There are 4 cards (10, J, Q, K) out of every 13 that have a value of 10. That means there are 9 cards out of 13 that have a different value. In that case, the dealer would have a 69% chance of having something other than a 10 in the hole and a 69% chance of winning the insurance side bet.
For that reason, you shouldn’t take insurance when it is offered to you. In fact, as a general rule you should avoid any side bets in blackjack, because almost all of them have a higher house edge than the regular game. The only exception is if you are counting cards, which you can’t do at an online casino, and determined that the deck is rich in tens. In all other situations, if the dealer offers you insurance, say thanks, but no thanks.