Blackjack: Always Split 8's. Why?

Playing Blackjack on a popular gaming site, the “Hint” function, whenever I’m dealt two 8’s, says “Always split Aces and 8’s.” I can see why should always split Aces (since they’re such powerful cards), but the math isn’t working for me on the 8’s.

Can someone please give me a layman’s explanation?

Short answer, two eights are 16, always a loser if the dealer doesn’t bust. Split them, you’ll probably get at least one face card to make an 18. You don’t split nines or tens because they’re winners, and you don’t split winners.

Similarly, you should “always” split Aces, because together they are only 2 or 12, and headed for 22, but separately, they are potential 21s.

Much of blackjack strategy is premised upon the fact that 4/13ths of the deck is made up of cards that count for 10. That’s 30% of the deck.

What about splitting 7s? 14 is not a good hand, but the potential for 1 or 2 17s is decent.

Depends on what the dealer is showing. If the dealer has a seven or better, you’ve got a good chance of losing twice if you split. If you draw a card with fourteen you can’t bust more than once.

17 isn’t a very good hand. With two 17s you’re likely to lose twice.

Ok, so if the dealer shows a 5 or 6, would you split 7s?

I would. If the dealer is showing a bust card, go for it any time you can.


Assuming the following :

8 decks
can double after split
double on any 2 cards

splitting 7s against a dealers 5 would earn you $1.16 for every dollar in your original stake.
splitting against a 6 would get you $1.25.

However, against a 7, splitting would still be the best option, but you would expect to get $0.95 and against an 8 you’d be better off hitting.

Wikipedia: Basic strategy for blackjack play. You split 7’s on any dealer card 2 through 7. So the above posters were not completely correct, based on basic strategy.

And keep in mind, there are more tens in the deck than anything else. Remember that always.

The average hand in blackjack is 17.5. If you split the eights and hit a face card, a 10, or an ace, you’re beating the average. Don’t split nines because it’s a stronger hand (18).


Similarly, I do not believe your best bet on double 8’s is splitting if the dealer’s showing 9 or 10; you’re simply making it likely you will lose twice.

If you have a pair of 8s against a dealers 9 or 10, chances are you are going to lose whatever you do. However, on average you will lose less if you split.

vs a 9

stand : -0.54
hit : -0.506614
double : -1.01
split -0.39
vs a 10

stand : -0.54
hit : -0.54
double : -1.07
split : -0.476849
in either case, splitting is still your best option.

Thanks, Peter. Tricky thing, probabilities. :smiley:

Basic strategy is to split 9’s vs. dealer 2-6, 8-9.

Given you have an 18 and you don’t know what the dealer has (other than dealer doesn’t have blackjack), it’s BARELY a winning hand (EV +0.03).

This is a little misleading, what you really want is the median hand. Also, keep in mind that the median hand loses because that’s how the casino makes its money.

Again, given that you don’t know anything about what the dealer has other than no blackjack,

Anything below 16: -0.42
17: -0.27
18: +0.03
19: +0.32
20: +0.66

17 sucks, even against dealer 6 (+0.01) and dealer 5 (-0.04). 18 isn’t that great against anything but dealer 3-6. 19 is the first hand that is an expected winner no matter what dealer is showing, and even then, it’s barely winning against dealer 10 (+0.06).