Blackjack basic strategy is important if you want to lower the house edge for the game to an acceptable level. If you’re reading this blackjack blog, you probably already know that. Sometimes people deviate from basic strategy, though. This is done because they forget the real strategy and because they use flawed logic to come up with what they think is the answer. On occasion, they also do so because they think that basic strategy is wrong.
One common mistake that makes me cringe is when people split a pair of tens. You should never split a pair of tens, but people do. When they do, it is based on what would otherwise be good strategy. Tens are good cards to start a hand with. In fact, next to an ace, it’s the best card to draw with your first card. The thinking then is if you have a pair of tens, you can split it and you will have two hands starting with a ten, which is twice as good.
People who succumb to that type of thinking forget to do one simple thing: add their cards. A pair of tens equals a hand of 20, which can only be beaten by a hand of 21. Needless to say, a hand of 20 is a great hand to have and you don’t want to give it up. But what are the odds if you do?
Starting a hand with a 10, you have a 1/13 chance of improving your hand, since only an ace would give you a 21. You have a 4/13 chance of ending up with another hand of 20 (by drawing a 10, J, Q or K), which is what you had before splitting the pair. That leaves a 9/13 chance that you will end up with a hand worse than 20.
That is for one hand. By splitting a pair of tens, you’re starting two hands with a ten, which means both hands have a 69% chance of ending up worse than where you started. With that in mind, it is clearly a better idea to stand, take your hand of 20 and hope to beat the dealer. After all, only a dealer 21 can beat you and a dealer 20 will only tie you. You win against any other dealer hand.
As always, basic blackjack strategy works in online casinos as well as the brick and mortar variety.