Why am I always supposed to split Aces and 8s in Blackjack?

The aces are easy—you will have two chances to get 21!

With 8s, mathematical analysis shows that splitting them loses less often over the long run than any other move you could make. 

In most versions of Blackjack, when you are dealt a pair (two of the same card), you have the option to split them into two new hands. When you split, you must match your bet on the new hand, effectively doubling the amount wagered.

You now have two chances to beat the dealer.

Why split two Aces?

Should you receive two aces, the split is an easy move because an Ace is the most powerful card in Blackjack. Any card drawn next that is valued at 10 gives you 21.

The deck has more 10-value cards than any other single value—10s, Jacks, Queens, and Kings all count as 10. So, you combine an Ace with the higher probability of drawing a 10-value card, thus increasing your chances of beating the dealer and winning.

Splitting Aces every time is mathematically the best move possible, against any possible dealer up-card.

Note: After splitting those Aces, the dealer will give you only one additional card per Ace. Any draw of a 10-card is considered a total of 21 not Blackjack, so you’ll be paid even money for a winning hand.

What are your other options?

You could refrain from splitting, and the aces can count as either a 1 or an 11, following, you would continue to hit until you are satisfied or you bust.

Why split two 8s?

The hard fact is that the dealer is favored to win when you hold a pair of 8s.

Together, your cards total 16–the weakest, most dangerous hand in Blackjack. The most likely single card to draw in any situation is a 10 card, as mentioned, because each deck has more 10-cards than any other value.

Draw a 10 against your two 8s, combining for 16, and you bust. As a matter of fact, any card over 5 will bust you.

Splitting 8s is very much a move that basic strategy players swear by.

It is actually pretty easy to explain why two hands starting with an 8 have a lot more potential than a hard 16 as there is a very understandable logic behind this classic basic strategy defensive move.

Basic strategy assumes that 10s would be drawn because there are more of these in play than any other card value. In other words, splitting 8s offers players the chance to get two hands of 18, and 18 is a good, if not excellent, point value.

But what if the dealer is showing a 10 card? Why would you want to split two 8s against a dealer’s 10 and possibly create two losing hands instead of one?

Simply put, the math says that over the long-term, you have the best chance of minimizing your losing hands by splitting the 8s. When you split 8s like any other pair (except Aces), doubling and re-splitting is allowed up to four hands.