Blackjack's Splitting Pairs
Anytime you're dealt identically ranked cards, you have the option to split them and play them as two separate hands. This means that your original bet will now double, since you must put down a bet equal to that bet on the split card. Let's see how this works.
Suppose you're dealt 8-8. You can split them by separating them. If you're in a game where the cards are dealt face down, you turn them over, separate the cards and put down an additional bet equal to your original one. If you're in a game where the cards are dealt face up, you simply separate the cards and make an additional bet on the separated card.
Now that you've separated the two 8s, you play them as original hands. Let's assume that with first original 8 you hit and get a 6. Now you have a 14 on the first hand. Let's say you hit that hand again and get a 10. You've gone over 21 and busted, and therefore the cards on that hand and the chips are taken away by the dealer.
Now you play the second hand. Let's assume that you hit and get an ace. You now have a soft 19, a strong hand and decide to stand. If you beat the dealer with that total or the dealer busts, you win that bet.
As we mentioned, you can split any cards of equal rank. You can split 2-2, 3-3, 4-4, and so forth. Any 10-value cards are considered of equal rank. Thus, if you're dealt a king and a jack, you can split them as 10s but this is not to say that all pairs should be split.
Some players think that if they've been dealt a pair, they should split them. This is a terrible and losing strategy. Only certain pairs should be split against certain dealer's upcards. Splitting pairs occurs much less often than doubling down, but it can be very profitable if done correctly.
Most casinos, with exception of the Atlantic City houses, will permit you to re-split pairs.
For example, if you've split 9s and get another 9 on either 9 split, you can re-split it. Suppose you play out the first 9 and get a 5 and stand with a hard 14. On the second 9 you get another 9. You can now re-split this 9 by putting out another bet equal to your original wager. If you get yet another 9, you can again re-split it.
Splitting Aces
A separate rule applies to the splitting of aces. If you split them, you're only allowed one additional card to be dealt to each ace, and if you get an ace on an ace, you can't re-split the aces. There are a few casinos that allow you to re-split aces, but none that I know that allow you more than one card on an ace that is split.
Doubling Down After Splitting
Here we combine doubling down and splitting of pairs. It works this way: Suppose you're dealt a pair of 8s and you split them, putting out a separate bet on each 8. On the first 8, which you hit, you're dealt a 3. No you have an 11, and in some casinos, you're permitted to double down after splitting so now you can double your bet on-this hand, and receive one additional card to your 8-3.
