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When to Split Pairs in Blackjack

Which pairs to split against each dealer card, and which never to split.

Basic strategy says
Always split aces and 8s. Never split 10s or 5s, and rarely split 4s.

Whether to split depends on your pair and on the dealer card. The chart below shows where splitting is right.

Pair splitting chart

Dealer stands on soft 17, double after split allowed, surrender not allowed.

2345678910A
A,APPPPPPPPPP
2,2PPPPPPHHHH
3,3PPPPPPHHHH
4,4HHHPPHHHHH
5,5DDDDDDDDHH
6,6PPPPPHHHHH
7,7PPPPPPHHHH
8,8PPPPPPPPPP
9,9PPPPPSPPSS
10,10SSSSSSSSSS
H HitS StandD Double (else hit) · Ds Double (else stand)P SplitR Surrender (else hit; 17 v A else stand; 8,8 v A else split)

With no double after split, the chart changes a little. See the full chart with rule options.

Each pair, one at a time

  • Aces (A,A): always split. Two aces start at 12 as a pair, but each ace alone gives you a great chance at 21. Most games give you one card on each ace.
  • Eights (8,8): always split. A hard 16 is the worst hand, and 8 is a much better place to start. (Rare exception: if surrender is allowed and the dealer hits soft 17, surrender against an ace.)
  • Tens (10,10 and any ten-value pair): never split. 20 wins most hands.
  • Nines (9,9): split against a dealer 2 to 6, 8 and 9. Stand against a 7 (your 18 beats the dealer's likely 17), a 10 and an ace.
  • Sevens (7,7): split against a dealer 2 to 7, hit against anything higher.
  • Sixes (6,6): split against a dealer 2 to 6 if you can double after a split, or 3 to 6 if you cannot. Otherwise hit.
  • Fives (5,5): never split. Treat them as a hard 10 and double against a dealer 2 to 9.
  • Fours (4,4): split only against a dealer 5 or 6 and only if you can double after a split. Otherwise hit.
  • Twos and threes (2,2 and 3,3): split against a dealer 2 to 7 if you can double after a split, or 4 to 7 if you cannot. Otherwise hit.

Why double after split matters

Double after split (DAS) means you may double down on a hand after splitting. Most games allow it. It makes small pairs more valuable, which is why 2s, 3s, 4s and 6s are split in more situations when DAS is allowed. If your game does not allow it, use the stricter rules above or switch it off in the chart or the calculator.

Good to know

  • Splitting means you put down a second bet equal to your first, so you have two hands.
  • Casinos have different rules about resplitting and about split aces, such as one card only. These small rules change the odds slightly but not the main advice here.
  • 10-value cards (10, J, Q, K) count as pairs of each other in most casinos, but you should never split them.

More blackjack strategy guides

Blackjack basic strategy chartA printable chart for hard totals, soft totals and pairs that changes with your table rules.16 against a dealer 10Hit, stand or surrender? The numbers behind blackjack's most famous decision.Soft hands strategyHow to play soft 13 to soft 20, such as ace and 7 or ace and 6.When to surrenderThe few hands where giving up half your bet is the best move.Dealer hits or stands on soft 17What the rule changes and which plays are different.

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Frequently asked questions

Should I always split 8s?

Yes. A pair of 8s is a hard 16, the worst hand in blackjack, and splitting gives you two hands that start at 8. The one exception is if surrender is allowed and the dealer hits soft 17, where surrendering against an ace is slightly better.

Should I ever split 10s?

No. 20 is a very strong hand. Splitting gives up a hand that wins most of the time for two hands that win less.

What should I do with a pair of 5s?

Do not split. Treat them as a hard 10 and double against a dealer 2 to 9. Hit against a 10 or ace.

What should I do with a pair of 9s?

Split against a dealer 2 to 6, 8 or 9. Stand against a 7, 10 or ace.

Does the dealer soft 17 rule change when to split?

It barely changes splitting. The one case is 8s against an ace when surrender is allowed. The soft 17 rule affects doubling and surrender much more. See the dealer soft 17 guide.