← Back to Trainer

Blackjack Splitting Pairs

When you're dealt two cards of the same rank, you can split them into two separate hands. Used correctly, splitting turns bad hands into profitable situations and gets more money on the table when the dealer is weak.

How splitting works

When your first two cards are the same rank, you can place a second bet equal to your original and split the pair into two separate hands. Each hand gets a new second card and plays independently. If you split aces, most casinos only deal one additional card per ace and you cannot re-hit.

Split rules at most US casinos
You can split any pair (same rank)
Second bet must equal your original bet
You can split up to 3 times (4 hands total) — except aces
Split aces get one card each, no re-hitting
Double after split (DAS) is usually allowed

The quick rules: always, never, sometimes

Always split — no exceptions
A,A
Aces
8,8
Eights
Never split — no exceptions
10,10
Tens / face cards
5,5
Fives

Full splitting strategy (6-deck S17, DAS)

Your pairSplit against dealerOtherwise
A,AAlways
10,10NeverStand
9,92–6, 8–9Stand vs 7, 10, A
8,8Always
7,72–7Hit
6,62–6Hit
5,5NeverDouble vs 2–9, Hit vs 10/A
4,45–6 only (DAS)Hit
3,32–7Hit
2,22–7Hit

6-deck, S17, double after split allowed. DAS = double after split.

Why always split aces

An ace is the most powerful starting card in blackjack. Starting two separate hands each with an ace gives you a strong chance of reaching 21 or a high soft total on each. Even though you only get one card per split ace, the expected value of splitting is substantially higher than playing Ace-Ace as a soft 12.

Why always split 8s (even vs a 10)

Hard 16 is the worst hand in blackjack. Against a dealer 10, you will lose money whether you hit, stand, or split 8s — but you lose the least by splitting. Each hand starting with an 8 has much better expected value than playing 8-8 as a hard 16.

8,8 vs dealer 10
Stand on hard 16Lose ~54¢ per $1
Hit hard 16Lose ~54¢ per $1
Split 8sLose ~48¢ per $1

Splitting 8s vs a 10 is still a losing play — but it's the least losing option.

Why never split 10s

A pair of 10s is a 20 — one of the strongest hands in blackjack. You will win this hand the vast majority of the time. Splitting turns a near-certain winner into two hands each starting at 10, which is good but not as good as the 20 you already have. Never split 10s, no matter what the dealer shows.

Never split 10s — even vs a dealer 6

Some players split 10s against a weak dealer upcard hoping to "get more money down." The math doesn't support it. Stand on 20 every time.

Why never split 5s

Two 5s make a hard 10 — one of the best doubling hands in blackjack. Splitting turns that into two hands each starting at 5, which is weak. Always treat 5,5 as a hard 10: double against a dealer 2–9, hit against 10 or ace.

Frequently asked questions

When should you split in blackjack?
Always split aces and 8s. Never split 10s, 5s, or 4s (except 4s vs 5 or 6 with DAS). Split 9s vs 2-6 and 8-9. Split 7s and 6s vs 2-7 and 2-6 respectively. Split 2s and 3s vs 2-7. These rules apply to a 6-deck S17 game with double after split.
Should you always split aces in blackjack?
Yes, always. Starting two hands with an ace each is significantly more profitable than playing ace-ace as a soft 12. Even though most casinos only deal one card per split ace, splitting is always correct.
Should you split 8s against a dealer 10?
Yes. Hard 16 is the worst hand in blackjack and you lose money no matter what — but splitting 8s loses less than hitting or standing. Each hand starting with an 8 has better expected value than playing 16.
Should you ever split 10s in blackjack?
No, never. A pair of 10s is a 20, one of the strongest hands in blackjack. Splitting destroys a near-certain winner. Stand on 20 every time, regardless of the dealer upcard.
What is double after split in blackjack?
Double after split (DAS) lets you double down on the first two cards of a split hand. Most US casinos offer DAS. It makes a few additional splits profitable, such as 2,2 and 3,3 against a dealer 2 or 3.
Practice splitting decisions for free

Blackjack GTO flags every splitting mistake and explains the correct play. Every pair combination is covered with real-time feedback. No money, no sign-up.

Open the trainer →